DirectX Diagnostic Tool (dxdiag) in Windows 11 and 10

If you came here to download the DirectX Diagnostic Tool, stop. There is nothing to download.

Press Windows + R, type dxdiag, press Enter.

It opens in about three seconds, because it has been sitting on your PC since the day Windows was installed. It ships inside every copy of Windows 11 and Windows 10, and has done since Windows 98. Every site offering you a "DirectX Diagnostic Tool download" is selling you something you already own — and a fair number of them wrap it in adware.

The harder question is what to do with the wall of numbers it shows you. That is most of this page: every field, what a healthy machine looks like, and how to use it to work out why a game will not start.

The Laptop That Would Not Run a Game

Jake runs a small mobile phone shop. He does not advertise PC repairs, but people bring him laptops anyway, because he is the only person on the street who will look at one.

A regular customer brought in her son's laptop. The boy had bought an older game in a sale, and it refused to start — a small grey box saying d3dx9_43.dll is missing from your computer. Jake charges ₹500 for a look. He said it would take twenty minutes.

Three hours later he had installed something called a "DirectX Repair Tool" from the second search result, watched it change the laptop's browser homepage, spent forty minutes undoing that, downloaded the missing DLL from a file site, got a second missing-DLL error, downloaded that one too, and finally stared at a machine that now had two unsigned files in its system folder and still would not run the game.

He refunded the ₹500 and did not charge for the three hours.

"Ethan," he said that evening, "I need to understand what DirectX even is. Because I was clicking on things for three hours and I never once knew what I was doing."

"Right. And here's the part that will annoy you," Ethan said. "The tool that would have told you what was wrong in ninety seconds was already on that laptop. It's been on every Windows PC you've ever touched. Nobody ever tells you it's there, because nobody makes money telling you that you already have something."

"So the fix was free and already installed."

"The diagnosis was free and already installed. The fix is one genuine Microsoft download, and it is not the one you'd guess from the error message."

What the DirectX Diagnostic Tool Actually Is

Two things need explaining before the tool makes any sense: what DirectX is, and what "diagnostic" means here.

DirectX, explained without jargon

A game does not know what graphics card you own. It cannot — there are thousands of models from three manufacturers, each with its own internal design.

So the game does not talk to your graphics card. It talks to DirectX, which is a set of instructions built into Windows. The game says "draw a triangle here, with this texture". DirectX translates that into whatever your specific card understands and hands it over. Your graphics driver is the piece on the other side that does the translating.

Ethan's version: DirectX is a receptionist. The game never meets the hardware. It hands its requests to the receptionist, who knows which door to take them to. Swap the hardware, and the game does not notice, because it was only ever talking to reception.

That is also why so much goes wrong at this exact layer. Three separate parties have to agree — the game, DirectX, and your driver — and a version mismatch between any two of them produces an error that reads like gibberish.

And dxdiag is the clipboard, not the toolkit

The DirectX Diagnostic Tool walks around your PC, asks every graphics, sound and input device what it is, which driver it is running and what it can do, and writes the answers on a form.

That is all it does. It is read-only. It installs nothing, changes nothing, updates nothing and repairs nothing. If you close it, your PC is byte-for-byte what it was before.

The three jobs it is genuinely good at

1. Answering "what graphics card is in this machine?" in one window, with the driver version and date, which Device Manager makes you dig for.
2. Producing the report file that support teams ask for. When a game studio says "attach your dxdiag", this is the button they mean.
3. Surfacing problems Windows already knows about. Each tab has a Notes box at the bottom. On a healthy machine every one of them says No problems found. When one doesn't, you have your answer in about four seconds.

And one thing it is quietly useful for that nobody mentions: proving a negative. When a customer insists their laptop has a dedicated graphics card, dxdiag settles it in one glance. Jake now opens it before quoting on any "it won't run my game" job.

There Is Nothing to Download. Really.

"DirectX diagnostic tool download" is one of the most-searched phrasings of this topic. It deserves a straight answer, because the honest one is unusually clear-cut.

The file already exists on your computer. Right now. Here:

C:\Windows\System32\dxdiag.exe

Paste that into the Run box and press Enter to prove it. There is a second, 32-bit copy at C:\Windows\SysWOW64\dxdiag.exe, which matters only in one edge case covered further down.

It is a Windows component. It arrives with Windows, it is serviced by Windows Update along with everything else, and Microsoft does not distribute it separately — there is no page on microsoft.com where you can download dxdiag on its own, because the concept does not exist.

So what are those download sites actually giving you?

One of four things, in descending order of how often we see them:

None of those four is ever the right outcome, because in all four cases the thing you wanted was already installed.

Checking that the dxdiag on your PC is the real one

Worth doing once if you have already installed something dubious. Malware likes this filename precisely because it looks like it belongs.

1. Open File Explorer and go to C:\Windows\System32.
2. Find dxdiag.exe, right-click it, choose Properties. On Windows 11 you may need Show more options first — see the box in the next section.
3. Click the Digital Signatures tab. It must list Microsoft Windows as the signer.
4. On the Details tab, the file description reads Windows Direct X Diagnostic Tool and the copyright is Microsoft's.

No Digital Signatures tab at all, or a signer that is not Microsoft, means the real file has been replaced. That is a full malware investigation, not a DirectX problem. A copy of dxdiag.exe sitting in your Downloads folder or on your Desktop is not the Windows one and should be deleted; the genuine article never lives there.

How to Open dxdiag on Windows 11

Five routes. The first one is the only one worth memorising.

1. The Run box (fastest, works everywhere)

1. Press Windows + R.
2. Type dxdiag.
3. Press Enter.

What the Run box is, if you have never used it: a small dialog in the bottom-left corner where you can type the name of a program and launch it directly, skipping the Start menu entirely. It has been in Windows since 1995 and it is the fastest route to most of the administrative tools. You do not need to type .exe; Windows adds it. You do not need administrator rights for dxdiag.

If nothing happens, you may have typed it into the wrong window — the Run box is easy to lose behind a full-screen game.

2. Start menu search

Click Start (or press Windows), type dxdiag, press Enter. Windows 11 will show it under Best match as dxdiag or Run command.

Slower than the Run box because Windows 11 search insists on also querying the web, which on a weak connection means a two-second pause and a Bing result you did not ask for.

3. From Command Prompt, PowerShell or Terminal

Type dxdiag and press Enter. The graphical window opens as usual — it is not a command-line tool.

Useful when you are already in a terminal working through a repair, and essential for the scripted version further down. You do not need to run it as administrator, though it does no harm.

4. Straight from File Explorer

Paste C:\Windows\System32\dxdiag.exe into the File Explorer address bar and press Enter. Handy when you suspect something has interfered with how Windows resolves program names.

5. Task Manager, for when the desktop is unresponsive

Press Ctrl+Shift+Esc to open Task Manager, then Run new task and enter dxdiag. This is the route that still works when Explorer has crashed and there is no Start menu to click.

The prompt on first run, and the 64-bit question

The first time you ever run dxdiag, some builds ask: "Do you want to check if your drivers are digitally signed?"

Click Yes. It costs a few extra seconds and it fills in the WHQL Logo'd field, which is one of the fields actually worth reading. If you say No, that field shows nothing useful. The prompt only appears once.

You may also see a progress bar reading Loading... along the bottom edge with a percentage. dxdiag is querying each device in turn. Wait for it to finish before reading anything — the fields fill in progressively and a half-loaded Display tab has misled a lot of people.

On a 64-bit copy of Windows — which is essentially all of them now, and certainly all of Windows 11 — typing dxdiag launches the 64-bit version. If you happen to launch the copy in SysWOW64 instead, you get the 32-bit build, which adds a Run 64-bit DxDiag button at the bottom. The reports are near-identical; the 64-bit one is the one to send to support. Not sure which Windows you have? Our guide to checking whether your PC runs 32-bit or 64-bit Windows takes ten seconds.

Opening dxdiag on Windows 10

These steps are identical on both operating systems. Not similar — identical. Windows + R, type dxdiag, Enter. Same window, same four tabs, same fields, same buttons, same file path.

We are saying that explicitly because a great many pages present separate Windows 10 and Windows 11 instructions for this tool, which implies a difference that does not exist and makes the reader hunt for a distinction they will never find.

Three genuine differences show up in what the tool reports, not in how you use it:

That second row is worth a moment. Windows 11 requires a DirectX 12 compatible graphics chip with a WDDM 2.0 driver as a hard minimum. It is one of the less-discussed requirements — everyone argues about TPM 2.0 — but it is the one that rules out a lot of older business desktops with integrated graphics. If you are working out whether a machine can move, our Windows 11 system requirements guide covers the full list, and the Display tab you are about to read answers the graphics half of it directly.

And the honest note that belongs in every Windows 10 article now: Windows 10 reached end of support on 14 October 2025. dxdiag still runs, your games still run, but there are no more security updates unless you are enrolled in Extended Security Updates. Graphics vendors have also begun ending Windows 10 driver support for newer cards, which means the driver date you are about to look up will stop advancing on those machines. Our guide on what Windows 10 end of support actually means covers the options.

Reading the System Tab

This is where dxdiag opens. Most of it is a summary of things you can find elsewhere; two lines matter a great deal.

The DirectX Version line, and what it does not mean

On every Windows 11 and Windows 10 machine, this line reads DirectX 12. On a 2013-vintage laptop with integrated graphics from 2009. On a machine that cannot run a single DirectX 12 game. Still DirectX 12.

That is not a bug. The line describes the runtime Windows installed, not what your hardware can do. Windows 11 ships the DirectX 12 runtime to every PC regardless of what is inside it, so on Windows 11 the line carries essentially zero diagnostic information.

The number people actually want — can my card run this game — is the Feature Levels line on the Display tab. If someone tells you to "check your DirectX version in dxdiag" to see whether a game will run, they have sent you to the wrong line.

Two System tab fields with a use beyond DirectX

System Model is the single most useful string on this tab. Search that exact text plus the word "drivers" and you land on the manufacturer's support page for your precise machine — which is where laptop graphics drivers should usually come from, because laptop makers customise them. Our guide to updating drivers in Windows covers the order to do it in.

BIOS gives you a version and a date in one line, without rebooting. If you are troubleshooting a graphics card that is newer than the motherboard, an out-of-date BIOS is a real suspect. Our guide on finding your BIOS version shows the PowerShell route and explains what the version string means.

Reading the Display Tab (the One That Matters)

If dxdiag has one reason to exist, this tab is it. Nine times out of ten the answer to "why won't this game run" is somewhere on this screen.

Here is what the saved report looks like for a healthy laptop — a real capture from the test machine, trimmed:

---------------
Display Devices
---------------
          Card name: NVIDIA GeForce RTX 3050 Laptop GPU
       Manufacturer: NVIDIA
          Chip type: NVIDIA GeForce RTX 3050 Laptop GPU
           DAC type: Integrated RAMDAC
        Device Type: Full Device (POST)
     Display Memory: 8081 MB
   Dedicated Memory: 3985 MB
      Shared Memory: 4096 MB
       Current Mode: 1920 x 1080 (32 bit) (144Hz)
      Monitor Model: BOE0A1B
        Driver Name: nvldumdx.dll,nvwgf2umx.dll
     Driver Version: 32.0.15.6094
  Driver Date/Size: 12/09/2025 05:30:00
        WHQL Logo'd: Yes
        DDI Version: 12
     Feature Levels: 12_1,12_0,11_1,11_0,10_1,10_0,9_3,9_2,9_1
       Driver Model: WDDM 3.1
Driver Attributes: Final Retail
DirectDraw Acceleration: Enabled
Direct3D Acceleration: Enabled
AGP Texture Acceleration: Enabled
              Notes: No problems found.

A small thing that confuses people comparing notes: the on-screen labels and the saved file's labels are not the same. The window says Name, Approx. Total Memory and Display Memory (VRAM); the text file says Card name, Display Memory and Dedicated Memory. Same values, different wording. Nothing is wrong.

The Device section, field by field

Name / Card name — your graphics chip. This is the answer to "what graphics card do I have". If it says Intel UHD Graphics, Intel Iris Xe or AMD Radeon Graphics with no model number, that is integrated graphics built into the CPU, not a separate card.

Manufacturer — NVIDIA, AMD, Intel, or occasionally the laptop brand. Tells you whose driver page to visit.

Chip Type — usually a repeat of the Name. When it differs, trust Chip Type; it comes from the hardware, while Name can come from the driver.

DAC Type — ignore it completely. A DAC converted a digital signal to analogue for a VGA monitor. Nothing has used one since roughly 2008. The field survives because removing things from dxdiag would break tools that parse it.

Device Type — Full Device (POST) means this is the chip that displayed your boot screen. On a hybrid laptop the dedicated GPU often reads Full Device without POST, which is normal and simply means it does not drive the built-in panel directly.

Approx. Total Memory / Display Memory — the big one. Explained on its own below, because it causes more confusion than any other field in the tool.

Current Display Mode — resolution, colour depth and refresh rate. A quick sanity check: if you paid for a 144 Hz screen and this says 60 Hz, your refresh rate is set wrong in Windows and you have been getting the cheaper experience the whole time. That one line has paid for a lot of monitor purchases retrospectively.

Monitor / Monitor Model — a code like BOE0A1B is a panel identifier, not a fault. Search it if you want to know which panel your laptop has.

The Drivers section — where problems actually live

If a component on this screen is going to be the cause of your problem, it is almost always this one.

Driver Version — a four-part number like 32.0.15.6094. Not human-friendly. The last three or four digits map to the version the manufacturer advertises: NVIDIA would call that one 560.94. AMD and Intel use their own schemes. You do not need to decode it — you need to compare it with what is currently on the vendor's site.

Driver Date — the single most useful field on the tab. It is the date the driver was built, and it tells you at a glance whether you are running something current or something Windows installed generically years ago.

That last row deserves emphasis. 21/06/2006 is the fixed date Microsoft stamps on its fallback display driver. If you see it, Windows never found a proper driver for your card and is running a minimal one that can paint a desktop and nothing else. Games will refuse to launch, video will stutter, and no amount of DirectX installing will help. That single date has solved more "my game won't start" cases than any other field in this tool.

WHQL Logo'd — Yes means the driver passed Microsoft's Windows Hardware Quality Labs test suite. No usually just means you installed a very new or beta driver straight from NVIDIA, AMD or Intel before certification completed. Not automatically a problem. But if you are chasing intermittent crashes, going back to a WHQL-certified driver is a cheap way to eliminate a variable.

Driver Model — WDDM stands for Windows Display Driver Model, the rulebook graphics drivers follow. WDDM 3.x on Windows 11, 2.x on Windows 10. Higher is newer. You will essentially never need to act on this field, but games and Windows 11's own requirements refer to it.

Feature Levels — the line that answers the real question

This is what people mean when they ask which DirectX their card supports.

A feature level is a fixed bundle of capabilities that a chip either fully supports or does not. There is no partial credit. dxdiag lists every level yours can handle, highest first.

Two things to take from that table. First, seeing 9_1 in the list does not mean your card is old — a brand new RTX card lists 9_1 too, because it supports everything below it. Read the first number. Second, a modern card reporting only 11_0 is a strong hint that the correct driver is not installed, since feature level is reported by the driver.

The DirectX Features box, and why it always says Enabled

Three lines: DirectDraw Acceleration, Direct3D Acceleration and AGP Texture Acceleration, each with an Enabled or Disabled and a Disable button beside it.

On Windows 11 and Windows 10 these are close to meaningless. All three read Enabled on essentially every working machine, and the ability to turn them off was removed years ago — the buttons are greyed out. AGP in particular is a slot standard that stopped being manufactured around 2006; the line survives purely so that report-parsing tools do not break.

If any of them reads Disabled or Not Available, do not go hunting for a setting to flip. It is a symptom, not a cause, and it means the same thing as the 2006 driver date: hardware acceleration is not working because the driver is missing or broken.

Two Display tabs, and which one your game is using

Open dxdiag on a laptop and you may see Display 1 and Display 2. Some hybrid machines label the second one Render instead. Neither is a fault.

Almost every laptop sold in the last decade has two graphics processors:

• Integrated — built into the CPU, Intel or AMD, low power, weak, and what runs your desktop and browser so the battery lasts.
• Dedicated — a separate chip, NVIDIA or AMD, powerful and thirsty, meant to wake up only for demanding work.

Windows is supposed to hand games to the dedicated one automatically. It frequently does not — particularly for older games, launchers, emulators and anything running through a compatibility layer. The result is a machine with a perfectly good graphics card producing eleven frames a second, and an owner convinced the card is faulty.

To force it, on Windows 11: Settings → System → Display → Graphics, find the game in the list (or Browse to its .exe), click Options, choose High performance, Save. On Windows 10 the same page lives at Settings → System → Display → Graphics settings. NVIDIA Control Panel and AMD Software offer their own per-application setting that does the same job.

Then reopen dxdiag while the game is running and check which adapter reports activity, or use Task Manager's Performance tab, which shows both GPUs live and settles the argument in about four seconds.

The Sound and Input Tabs, Briefly

Shorter section, because these tabs genuinely matter less — but each has one job it does better than anything else in Windows.

Sound

You get one tab per audio output device, so a desktop with speakers, an HDMI monitor and a USB headset shows three. Each lists a Name, a driver Provider, a Version and a Date, with the same WHQL field as the Display tab.

Its one genuinely useful job: answering "how many audio devices does Windows think I have?" When sound is coming out of the wrong place, or an HDMI monitor has silently become the default output, these tabs show you every candidate at once, including the ghost entries left behind by uninstalled software. Driver date rules apply exactly as above.

Input

Lists every keyboard, mouse, gamepad and joystick, plus a long Input Related Devices section built from raw USB identifiers.

Its one genuinely useful job: confirming that a controller is reaching Windows at all. If your gamepad appears here but not in the game, the problem is the game or its input mode, not the hardware or the cable. If it does not appear here either, it is a cable, port or driver issue and there is no point touching game settings. That is a five-second test that saves a long evening.

The Notes box — read this first, always

Every tab has a Notes box at the bottom. It is small, grey, easy to skip past, and it is the highest-value thing on the screen.

On a healthy machine each one reads No problems found. When it does not, Windows is telling you directly what it has already detected — a driver that failed to load, a device that is disabled, a certificate problem. You are being handed the answer.

Ethan's habit, and now Jake's: click through all four tabs and read only the Notes boxes first. If they are all clean, the fault is not something Windows has already noticed, and you can move on to driver dates and feature levels. Thirty seconds, and it reframes the whole investigation.

Saving the Report: What Support Teams Actually Want

When a game studio, a GPU vendor or a hardware manufacturer says "send us your dxdiag", this is what they mean. Two clicks.

1. Wait for the loading bar at the bottom to finish.
2. Click Save All Information... at the bottom of the window.
3. Choose where to put it and click Save. The default name is DxDiag.txt.

It is a plain text file, typically 30 to 80 KB, that opens in Notepad. It attaches to an email or a support ticket without any conversion.

Why the file is more useful than the window

The saved report contains substantially more than the four tabs show. Sections that exist only in the file include:

• DxDiag Notes — all four Notes boxes collected in one place at the top.
• System Devices — the complete PCI device list, which is how a support engineer spots a chipset driver problem you would never have looked for.
• DirectShow Filters — every media codec and filter installed. This is where badly-behaved "codec packs" get caught.
• Sound Capture Devices and Video Capture Devices — microphones and webcams, which have no tab of their own.
• EVR Power Information — video playback power state.
• Disk & DVD/CD-ROM Drives with free space per volume.

That is why an attached report beats a screenshot every time, and why support teams keep asking for it after you have already told them your graphics card.

Generating it without opening the window

Useful for a shop like Jake's, where the same file gets produced on every machine that comes in:

dxdiag /t %USERPROFILE%\Desktop\dxdiag.txt

Run that in Command Prompt or PowerShell. No window appears; the file lands on the Desktop a few seconds later. Other switches worth knowing:

Use a full path, not a relative one — if you leave off the folder, the file goes to whatever directory the terminal happened to be in, and finding it later is its own small ordeal. If you want to script this across several machines, our PowerShell basics guide starts from zero.

Using dxdiag to Diagnose Real Problems

Everything above is reference. This is the part that turns it into a repair.

"This game says my graphics card is not supported"

Check three fields, in this order:

1. Driver Date. If it is 21/06/2006, stop — Windows is using its fallback driver and nothing will run. Install the real one.
2. Feature Levels. Compare the first entry against what the game asks for. 11_0 where the game wants DirectX 12 is a genuine hardware limit, and no download fixes it.
3. Which tab you are on. On a laptop, check both. Games often report the integrated chip because that is the one Windows handed them.

The order matters. Most people conclude "my card is too old" from step 2 without doing step 1, and buy hardware they did not need.

"It runs, but the frame rate is terrible on a good laptop"

Nearly always the wrong-GPU problem. dxdiag confirms the machine has the good chip; the fix is forcing the game onto it through Settings → System → Display → Graphics, as described above.

Second suspect: Current Display Mode reporting 60 Hz on a high-refresh screen. Third: the machine is on a power-saving plan that caps the GPU, which on laptops is frequently the whole story. If general sluggishness is the real complaint rather than games specifically, our guide to speeding up Windows 11 and 10 works through the startup programs and background services first.

"Display driver stopped responding and has recovered"

The screen goes black for a second, comes back, and a notification appears. Windows detected that the graphics driver stopped answering and restarted it rather than crashing the machine.

dxdiag's contribution: the driver version and date, so you know exactly what to roll back from or update to, and the Notes boxes, which sometimes name the failure directly. If it happens repeatedly, our dedicated guide on the display driver has stopped responding error covers the timeout setting, the overheating check and the driver rollback in order.

If the same fault escalates to a full crash instead of recovering, you are into blue screen territory, where the stop code names the driver file and dxdiag's version number tells you whether that file is current.

"My card has 8GB but dxdiag says 128MB"

You are on the integrated chip's tab. Click the next Display tab along. If there genuinely is only one tab and the machine should have a dedicated card, the card is either disabled in Device Manager, disabled in the BIOS, or has no driver installed — in which case it may be showing up under a Code 10 error instead of as a graphics adapter at all.

"The Notes box says something and I do not understand it"

Copy the text exactly and search it in quotes. These messages are generated from a fixed internal list, so the wording is identical on every affected machine worldwide — which means somebody has already asked about your exact string. This is the rare case where searching the literal error message genuinely works.

"dxdiag itself will not open"

In escalating order:

1. Use the full path. Win+R → C:\Windows\System32\dxdiag.exe. This rules out a broken path variable.
2. Try the 32-bit copy at C:\Windows\SysWOW64\dxdiag.exe.
3. If it opens and vanishes, a driver is crashing it mid-scan. Run dxdiag /dontskip and note which device it reaches before dying — that device is your fault.
4. Repair the file. Open Command Prompt as administrator and run sfc /scannow, which checks Windows' own files against known-good copies and replaces anything damaged. Takes ten to twenty minutes.
5. Test in a clean boot. If dxdiag works with third-party services disabled, something you installed is interfering; our clean boot guide narrows down which.

And the honest limit: if sfc /scannow reports corruption it cannot repair, no DirectX download will help you. That is a Windows integrity problem and the next step is DISM or a repair install — a different job entirely.

What dxdiag cannot tell you

Worth being straight about, because people over-trust it:

• Whether your card is overheating. No temperatures anywhere. Use Task Manager's Performance tab or a vendor tool.
• Whether your card is failing. A dying GPU reports its specifications cheerfully right up until it stops working.
• Live frame rates or usage. It is a snapshot, not a monitor.
• Whether a specific game will run. It gives you the facts to check against a requirements list. It does not do the checking.
• Anything about your power supply, which is the actual cause of a surprising share of "my graphics card crashes under load" complaints.

DirectX 9 vs 11 vs 12: They All Live Together

Here is the misunderstanding that has driven an entire category of search traffic for fifteen years, and that our own 2017 article helped along.

DirectX versions are not upgrades of each other. DirectX 12 did not replace DirectX 11 the way Windows 11 replaced Windows 10. They are separate sets of instructions that sit side by side in the same Windows installation, and a game calls whichever one it was written against.

Ethan's version: they are not software versions, they are languages. Windows is fluent in all of them. A game written in DirectX 9 gets answered in DirectX 9, on a machine that also speaks 12. Nothing needs downgrading, because nothing was ever replaced.

Two consequences worth stating plainly:

You cannot install DirectX 11 on a Windows 11 machine, because it is already there. Every page offering to sell or give you a DirectX 11 installer is selling you a file you have. Same for DirectX 12.

You cannot upgrade DirectX to raise your feature level. Feature level is determined by the graphics chip and reported by its driver. A card that tops out at 11_0 will report 11_0 forever, on any version of Windows, no matter what you install. If a game requires DirectX 12 hardware and your card is DirectX 11 class, the only fix is a different card.

Old Games, d3dx9_43.dll, and the Legacy Runtime

This is the one download that is real, and the section Jake needed three hours ago.

What is actually missing

DirectX 9's core is in Windows: d3d9.dll, ddraw.dll and friends are sitting in System32 right now on your Windows 11 machine.

But Microsoft also shipped a large set of optional convenience libraries alongside DirectX 9 — the D3DX family — that handled tedious jobs like loading a texture from a file or compiling a shader. Almost every game between roughly 2004 and 2012 used them, because writing that code yourself was pointless.

Those libraries were never part of Windows. They were always a separate redistributable that the game's installer was supposed to include. And they were versioned: d3dx9_24.dll through d3dx9_43.dll, a new one roughly every couple of months, each a slightly different build.

So the error is not "DirectX is missing". It is "this game needs the November 2010 build of a helper library that Windows has never included and your installer forgot to bring". Which is a much less alarming sentence.

The same family covers other filenames you will see in identical error boxes: xinput1_3.dll (controller support), xaudio2_7.dll and x3daudio1_7.dll (audio), d3dcompiler_43.dll (shader compiler), d3dx10_43.dll and d3dx11_43.dll. One download fixes all of them.

The fix: the DirectX End-User Runtime Web Installer

1. Go to microsoft.com and search for DirectX End-User Runtime Web Installer. Type the address yourself. Do not use a search result for "directx download", which is exactly where Jake went wrong. The genuine page is on microsoft.com and nowhere else.
2. Download dxwebsetup.exe — it is small, around 300 KB, because it fetches what it needs during installation.
3. Run it. Accept the licence. Watch for a bundled search toolbar offer on some older builds of this installer and untick it.
4. It downloads and installs the helper files into System32 and SysWOW64. Two to five minutes on a normal connection.
5. Restart the game. No reboot needed in most cases, though it does no harm.

What this does not do: it does not change your DirectX version, it does not downgrade anything, it does not touch DirectX 12, and dxdiag's System tab will read exactly the same afterwards. It adds files. That is all. Which is precisely why people run it, see no change in dxdiag, and assume it failed.

Why Windows Update will never fix this for you

A fair question: Windows updates everything else, so why not this?

Because the D3DX libraries are application dependencies, not operating system components. Microsoft's position has always been that the game is responsible for shipping them. They are also security-frozen — the last update to the DirectX 9 redistributable was in 2010, and Microsoft has no intention of pushing a decade-and-a-half-old library onto a billion machines that mostly do not need it.

So it will never arrive on its own, no matter how long you leave Windows Update running. This is one of the few remaining cases where a manual download really is the answer.

When the legacy runtime is not the answer

It fixes exactly one class of problem: a missing D3DX-family file. It will not fix:

• "Your graphics card does not support DirectX 11" — hardware limit, or a missing driver. Check Feature Levels.
• Crashes after the game has loaded — a driver, thermal or memory problem.
• Missing VCRUNTIME or MSVCP files — those are Visual C++ Redistributables, a different Microsoft package with a near-identical-looking error box.
• Games from before about 2001 that used pre-DirectX 8 interfaces. Those often need compatibility mode or a community patch, and sometimes cannot be made to work at all.

And a genuinely dead end worth naming: some very old titles rely on 16-bit installers, which 64-bit Windows cannot execute under any circumstances. No download, setting or compatibility mode changes that. Your options there are a virtual machine running an older Windows, or a re-release on a store like GOG that has already done the work.

Jake's customer's game, incidentally, was from 2009 and needed exactly the standard runtime. Four minutes, one Microsoft installer, and it launched. He has not charged for a diagnostic he could not complete since.

Questions People Actually Ask

Where do I download the DirectX Diagnostic Tool?

Nowhere. It is already on your PC at C:\Windows\System32\dxdiag.exe and has shipped inside Windows since 1998. Press Win+R, type dxdiag, press Enter. Any site offering it as a download is giving you something you own, usually with extras attached.

How do I open dxdiag in Windows 11?

Windows+R, type dxdiag, Enter. Or Start menu, type dxdiag, Enter. Or type it in Command Prompt, PowerShell or Terminal. Identical on Windows 10.

What does dxdiag actually tell me?

Your graphics, sound and input hardware; each one's driver version, build date and certification status; the DirectX feature levels your GPU supports; and any problems Windows has already detected, shown in the Notes box on each tab.

Does dxdiag fix problems?

No. It is read-only and changes nothing. It tells you which component is at fault so you fix the right thing, and it produces the report file support teams ask for. Guides that say "run dxdiag to fix DirectX errors" have misunderstood what the tool is.

How do I check my DirectX version?

System tab, bottom line, DirectX Version. On Windows 11 and Windows 10 it reads DirectX 12 on every machine. If what you really want is what your card can do, read Feature Levels on the Display tab instead.

Do I need to install DirectX 9 on Windows 11 or 10?

Not usually. DirectX 9's core runtime is already built in and runs alongside 11 and 12. What is missing is the optional D3DX helper libraries. If a game complains about a missing d3dx9 file, install the DirectX End-User Runtime Web Installer from Microsoft — it adds those files without changing your DirectX version.

How do I fix d3dx9_43.dll is missing?

Install the DirectX End-User Runtime Web Installer from microsoft.com, or run DXSETUP.exe from the game's own _CommonRedist\DirectX folder if it has one. Do not download the individual DLL from a file site — unsigned, unverifiable, and it will usually just produce the next missing-file error.

What does WHQL Logo'd mean in dxdiag?

Windows Hardware Quality Labs. Yes means the driver passed Microsoft's compatibility testing. No usually means a beta or brand-new vendor driver. Not automatically a fault, but worth reverting to a certified driver if you are chasing crashes.

Why does dxdiag show less video memory than my graphics card has?

You are probably reading the integrated chip's tab — check the other Display tab. Also, Approx. Total Memory adds dedicated VRAM and borrowed system RAM together, so it often reads higher than the number on the box. The figure games care about is Dedicated Memory.

Why does dxdiag show two display tabs?

Your PC has two graphics processors: an integrated one in the CPU for everyday work, and a dedicated one for demanding tasks. Each gets a tab. Some hybrid laptops label the dedicated one Render because no monitor is wired directly to it.

How do I save the dxdiag report?

Click Save All Information at the bottom of the window and choose a location. You get DxDiag.txt. Or skip the window entirely with dxdiag /t %USERPROFILE%\Desktop\dxdiag.txt in Command Prompt.

Is it safe to share my dxdiag report?

Privately with support, yes — it is routine. Publicly on a forum, edit it first: it contains your computer name, your Windows user name in every path, your machine's make and model, and every piece of media software installed. No passwords, keys or browsing history.

Why does dxdiag say DirectX 12 when my game needs DirectX 11?

Because they coexist. Windows ships DirectX 9, 10, 11 and 12 side by side, and a DirectX 11 game calls the DirectX 11 runtime directly. The System tab shows the newest present, not the only one. Your game is fine.

What are DirectX feature levels?

Fixed bundles of graphics capability that a chip either fully supports or does not. dxdiag lists every level yours handles, highest first. 12_2 is DirectX 12 Ultimate with ray tracing; 11_0 is a DirectX 11 class chip. This line, not the System tab, is what game requirements really mean. It is set by your hardware and cannot be raised by installing anything.

dxdiag will not open or closes immediately

Try C:\Windows\System32\dxdiag.exe in full, then the 32-bit copy in SysWOW64. If it flashes and vanishes, run dxdiag /dontskip to see which device kills it. sfc /scannow in an administrator Command Prompt repairs a damaged dxdiag.exe.

Is dxdiag different in Windows 11 and Windows 10?

The tool is effectively identical — same shortcut, tabs, fields and buttons. What differs is what it reports: WDDM 3.x on Windows 11 versus 2.x on Windows 10, and Windows 11 machines always show at least feature level 11_0 because DirectX 12 capable graphics is a Windows 11 requirement.

Is there a better tool than dxdiag?

For a quick, universal, already-installed snapshot, no. For deeper work: GPU-Z (free) shows live clocks, temperatures and real VRAM usage; Task Manager's Performance tab is built in and shows both GPUs live; and System Information (msinfo32) covers the whole machine rather than just DirectX. dxdiag's advantage is that it is on every Windows PC on earth and needs no installation — which is exactly why support teams ask for it.

What Jake Does Now

Every laptop that arrives at the counter with a game complaint gets the same ninety seconds: Win+R, dxdiag, read the four Notes boxes, check the driver date, check the feature level, check both Display tabs.

Most jobs are decided before he has touched anything. Roughly half are an out-of-date driver; about a quarter are the wrong GPU being used; a handful are the legacy runtime; and occasionally the answer is that the machine genuinely cannot run the game, which is worth knowing in ninety seconds rather than after a Saturday.

He has not installed a "DirectX Repair Tool" since.

If the driver turns out to be the culprit — which it usually does — our guide to updating drivers properly in Windows 11 and 10 is the next step, and it explains why Device Manager's "Search automatically" button almost never finds a newer graphics driver.

Related Guides

Originally published January 2017 as "DirectX 9 for Windows 10 — how to download". Completely rewritten and re-tested in 2026 for WIndows 11.