Find Your Windows Build Number (Windows 11 & 10): winver, CMD, Table

To find your Windows build number, press Windows + R, type winver and press Enter. The window shows a line like Version 25H2 (OS Build 26200.9457). You can also see it in Settings > System > About under Windows specifications, or by typing ver in Command Prompt. The number before the dot tells you which version of Windows you have: 26100 is Windows 11 24H2, 26200 is 25H2, 26300 is 26H2, and 19045 is Windows 10 22H2. The number after the dot tells you which monthly update you last installed. Here is why it matters this month in particular: if your build starts with 26100 and you run Home or Pro, Windows 11 24H2 receives its last security update on October 13, 2026. After that, that build stops getting fixes, and the build number is the fastest way to know whether that applies to you.

Ethan's aunt called the bank's help line about a login problem, and the first question was "What build of Windows are you on?" She had no idea what that meant. She read out "Windows 11 Home", which was not the answer, then "version 10.0", which was also not the answer and, confusingly, what Windows 11 itself reports in some places. She called Ethan, who was at Jake's shop. Jake had her press Windows + R and type winver. "Version 24H2, OS Build 26100.6584," she read. The help desk had what it needed in seconds. Jake noted something else: a 24H2 Home PC, with support ending in days. That is where this page starts: every way to find the build, what each part of the number means, the full build table, and what to do when your build has reached the end of its support.

Your build number is the most precise description of your Windows installation. "Windows 11" says which product you have, the version (such as 25H2) says which yearly release, and the build pins it down to the exact monthly update. Support teams ask for it, update guides depend on it, and known-issue lists are written against it. It takes ten seconds to find, and once you know how to read it, it also tells you how up to date your PC is and how long it will keep getting security fixes, which is far more useful than the product name on the box.

7 ways to find your Windows build number

1. winver. Press Windows + R, type winver, press Enter. A small "About Windows" box shows the version and OS build. It is the quickest method and works on every Windows version.
2. Settings. Open Settings > System > About (Windows + I, then System, then About at the bottom), or type ms-settings:about in the Run box. Under Windows specifications you see Edition, Version, Installed on, OS build and Experience.
3. Command Prompt. Type ver and press Enter. It shows something like Microsoft Windows [Version 10.0.26200.9457]. The third number is the build, the fourth the update revision.
4. systeminfo. In Command Prompt, systeminfo | findstr /B /C:"OS Name" /C:"OS Version" prints the name and the full build. Running plain systeminfo also lists installed updates.
5. PowerShell. Get-ComputerInfo -Property OsName, OsDisplayVersion, OsBuildNumber gives the product, the version such as 25H2, and the build. Details in the command section below.
6. Registry. The values live under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion: CurrentBuild, UBR (the number after the dot) and DisplayVersion (such as 25H2). Read only; there is no need to change anything here.
7. Windows Update history. Settings > Windows Update > Update history lists cumulative updates by KB number, which map to build revisions. Useful for seeing when your build changed.

For most people, winver is all they will ever need. The others matter when you need the number in a script, on a remote machine, or when Settings will not open.

Which method to use when

How to read a build number: 26200.9457 explained

A full build has two parts, separated by a dot. Take 26200.9457:

• 26200 is the base build. It identifies the Windows version, in this case Windows 11 version 25H2. It only changes when you move to a new version.
• 9457 is the revision, also called the UBR (update build revision). It goes up with each cumulative update, the monthly patch, so a higher number means a more recently updated PC on the same version.

Windows 11 24H2, 25H2 and 26H2 share the same underlying code base and are serviced with matching updates, so a single monthly update raises the revision on all three to similar numbers. That is why you sometimes see the same revision with different base builds, such as 26100.9457 and 26200.9457 from the same September update. The base build tells you the version; the revision tells you the patch level.

Two more lines in Settings > About are often confused with the build:

• Version (such as 25H2) is the friendly name for the base build. "H2" means the second half of the year it was released.
• Experience (such as "Windows Feature Experience Pack 1000.26100.x") is the version of some built-in apps and features that Microsoft updates separately. It is not your build number, and support teams rarely need it.

Windows 11 and Windows 10 build numbers, versions and release years

Find your base build in this table to see exactly which Windows you have.

Build 17763 is also the base of Windows 10 LTSC 2019 and Windows Server 2019, and 14393 of LTSB 2016 and Server 2016, which is why those numbers keep turning up in business environments long after the consumer versions retired. Windows Insider preview builds use much higher numbers that change weekly, and show a watermark in the corner of the desktop.

Is your build still supported? End dates that matter now

The build number is the key to the most important question about any Windows PC: is it still getting security updates? These are the dates for the versions most people have, for Home and Pro editions.

• 26100, Windows 11 24H2 (Home, Pro): support ends October 13, 2026. That month's Patch Tuesday is its last update. Enterprise and Education editions continue to October 12, 2027.
• 26200, Windows 11 25H2 (Home, Pro): supported to October 12, 2027.
• 26300, Windows 11 26H2 (Home, Pro): supported to October 10, 2028.
• 22631 and older Windows 11 builds: no longer supported on Home and Pro. Update to a current version.
• 19045, Windows 10 22H2: mainstream support ended in October 2025. Security updates continue only through the Extended Security Updates program, which our guide to Windows 10 ESU explains.

If your build is on its last month, the fix is usually easy. Open Settings > Windows Update and install the offered feature update. On 24H2, moving to 25H2 or 26H2 is a small enablement package and a single restart, because they share the same code base. If no upgrade is offered, the PC may be held back by a known issue, a compatibility hold or a policy; the Windows Update page usually says so.

Moving from 24H2 (26100) to 25H2 or 26H2

If winver shows 26100 on a Home or Pro PC, the move to a supported version is one of the easiest upgrades Windows has ever had, because 24H2, 25H2 and 26H2 share the same code base. The newer versions arrive as an enablement package: a small download that switches on features already present, followed by one restart.

1. Open Settings > Windows Update and install every pending update first. The 26H2 enablement package needs a recent cumulative update to be installed before it is offered.
2. Turn on Get the latest updates as soon as they're available on the same page. Feature updates roll out in phases, and this setting puts you earlier in the queue.
3. Click Check for updates. When the feature update to 25H2 or 26H2 appears, choose Download and install.
4. Restart when asked. One restart is usually enough, and it takes about as long as a normal monthly update.
5. Run winver again. The base build should now read 26200 or 26300.

If something goes wrong afterward, you can go back within ten days from Settings > System > Recovery > Go back, or remove the enablement package from Update history > Uninstall updates. Before any version change, it is still worth making sure your files are backed up.

Why your PC is not offered the newer version

Sometimes winver shows an old build and Windows Update offers nothing newer. The common reasons:

• A safeguard hold. Microsoft blocks the upgrade on PCs with a known compatibility problem, such as a driver or an app, until it is fixed. Windows Update usually shows a note that the update is not ready for your device yet. Waiting is the safe choice.
• A known issue on your hardware. New versions sometimes ship with known problems on specific setups; 26H2's release notes listed issues with some USB audio devices and with Credential Guard on domain-joined PCs, which our guides to USB audio Code 10 and the trust relationship error cover.
• A policy. On work PCs, IT may pin the version with a target-version policy. On personal PCs, leftover policies from old tweak tools can do the same.
• Pending updates. A failed or pending cumulative update blocks the feature update. Clear those first.
• Hardware requirements. PCs that were upgraded to Windows 11 despite not meeting its requirements may not be offered new versions automatically.
• Low disk space or a metered connection. Windows will not download large updates over a connection marked as metered unless you allow it.

How the number after the dot changes: the monthly update rhythm

The revision after the dot does not change randomly. It follows Microsoft's monthly update rhythm, and once you know it, the number tells a story.

• Patch Tuesday (the second Tuesday of each month) brings the security update every PC should install. It raises the revision. Microsoft calls these "B" releases.
• The optional preview update (usually the fourth week) brings non-security fixes early, for people who choose to install it from Windows Update's optional updates. It raises the revision again, and its fixes are folded into the next Patch Tuesday. These are "D" releases; the September 22, 2026 update, KB5124010, was one.
• Out-of-band updates fix urgent problems between the regular dates. The September 14, 2026 update, KB5129195, was an out-of-band release that fixed problems introduced by the September security update.

So two PCs on the same version can show different revisions simply because one installed the optional preview and the other waited. Both are fine, as long as each has at least the latest Patch Tuesday revision. If you ever see your revision go down after an update, an update was uninstalled or rolled back, which is worth knowing, because the security fixes in it went with it. Install pending updates again unless you removed one on purpose to work around a problem.

What actually changes between 24H2, 25H2 and 26H2

Because the three versions share one code base, the differences are smaller than past Windows upgrades, but they are real. Windows 11 26H2, build 26300, released in September 2026, brought a redesigned Start menu with a category and grid view, the option to move the taskbar to the top or sides and to make it smaller, app-specific actions on taskbar buttons, File Explorer improvements including support for more archive formats, Bluetooth LE Audio improvements, better resume for USB4 docks, Task Manager columns for the NPU, more languages for voice access, and a Braille Viewer for Narrator. Windows Update also bundles more updates together so PCs restart less often.

Some things went away too. WMIC, the old command-line management tool, is gone from current builds, and the old PowerShell 2.0 engine has been removed. Scripts that relied on either need updating, which is one reason admins check build numbers before rolling out a new version.

Many of the newer features also reached 24H2 and 25H2 through monthly updates, which is why two PCs on different versions can look almost identical. The practical difference that cannot be updated away is support: newer versions are supported longer.

Build numbers in error messages, logs and app requirements

Once you know your build, a lot of technical text becomes readable.

App requirements. Software often lists "Windows 10 build 19041 or later" or "Windows 11 22621 or later". Compare the base build: 26200 is higher than 22621, so you qualify. A lower number means the app will not install or may misbehave.

Event Viewer and crash reports. Error logs and crash dialogs often include the OS version as 10.0.26200.9457. That four-part form is version 10.0, build 26200, revision 9457. When you search an error message online, adding your base build to the search finds reports from people on the same version.

Release notes and known-issue lists. Microsoft's release notes are written per build ("Applies to: Windows 11, version 25H2, all editions; OS Builds 26100.x and 26200.x"). Matching your build to that line tells you whether a known issue or a fix applies to you.

Common mistakes when reading a build

• Reporting the version 10.0 instead of the build. Always give the five-digit build.
• Reading the Experience pack number as the build.
• Comparing revisions across different base builds. 22631.5000 is not newer than 26100.4000; the base build comes first.
• Assuming a higher number on a website means an update you are missing. Insider builds have much higher numbers and are not meant for most PCs.

Still on Windows 10? What build 19045 means now

If winver shows build 19045, you have Windows 10 22H2, the final version of Windows 10. There will be no 23H2 or later; Windows 10 receives only security fixes now, and only on PCs enrolled in Extended Security Updates. Without ESU, a Windows 10 PC no longer gets security fixes at all, which matters most for anything that handles banking, email or work.

Your options, from simplest to biggest: enroll in ESU to keep getting security updates while you plan (our Windows 10 ESU guide covers how and until when), upgrade the same PC to Windows 11 if it meets the requirements (the PC Health Check app tells you), or replace the PC. If your build is lower than 19045, such as 19044, install the 22H2 update from Windows Update first; it is a small enablement package on most PCs, and ESU requires 22H2.

A tip for checking quickly whether a Windows 10 PC is getting ESU updates: compare its revision after the dot with the latest Windows 10 security update's release notes. If the revision stopped climbing months ago, the PC is not receiving security fixes.

Should you install the optional preview updates?

Windows Update offers "optional" cumulative updates in the second half of each month. They carry non-security fixes early, before they reach everyone in the next Patch Tuesday update. Installing them raises your revision number sooner.

For most people, the sensible approach is: skip them unless they fix a problem you actually have. They are previews, and while they are generally stable, they are where new bugs occasionally appear first. If a release note for an optional update says it fixes the exact issue troubling you, such as a printing bug or a Bluetooth problem, it is worth installing early. Otherwise, the fix arrives with the next security update anyway.

Turning on Get the latest updates as soon as they're available makes Windows install new features from optional updates sooner. It is fine to leave on for curious users and off for anyone who prefers a calmer PC.

Keep a one-line record of your PC

Builds change monthly, and when something breaks, the first questions from any helper are always the same. A short note saved somewhere outside the PC answers them in one go: the model, the serial number, the edition, the version, the build and the BIOS version. Settings > System > About's Copy button gives most of it, and our guide to finding the BIOS version adds the rest. Update the build line after big updates. It turns a twenty-minute "what have you got?" conversation with any helper into a quick copy and paste, and it records when problems started, which is often the most useful clue of all.

Special cases: 26H1 on new PCs, and Arm laptops

Windows 11 26H1. Some brand-new PCs released in 2026, built around the newest processors, ship with a version called 26H1. It is a special branch for those devices only, with its own build numbers, and it is not something an existing PC can install. One practical consequence: PCs on 26H1 are not eligible for the 26H2 enablement package, and they follow their own update path set by Microsoft. If winver on a new laptop shows 26H1, that is expected, and it is fully supported.

Arm laptops (Snapdragon and similar). Windows on Arm uses the same version names and build numbers as Intel and AMD PCs, so the table above applies. Support can differ by chip, though. For example, PCs with the older Snapdragon 850 processor can install 26H2, but it is the last version they will get, with support running to October 2028. Check your processor in Settings > System > About under Device specifications if you own an older Arm laptop.

Windows in S mode shows the same build numbers too. S mode limits which apps you can install, not which version of Windows you run, so updating builds works normally.

Older PCs: Windows 8.1 and Windows 7

winver works on every Windows going back decades, so it is also the quickest way to identify an old PC someone hands you. Build 9600 is Windows 8.1, and 7601 is Windows 7 with Service Pack 1. Both stopped receiving security updates years ago, so neither should be used for online banking or email. If such a PC must stay in use, keep it off the internet, or move its files to a supported PC and retire it. A Windows 7 PC with build 7600 rather than 7601 never even installed Service Pack 1, which tells you it has not seen an update in a very long time.

Windows Server build numbers

Windows Server shares its builds with desktop releases, which is handy for admins reading logs and scripts:

• Windows Server 2025: build 26100, the same base as Windows 11 24H2.
• Windows Server 2022: build 20348.
• Windows Server 2019: build 17763, shared with Windows 10 1809 and LTSC 2019.
• Windows Server 2016: build 14393, shared with Windows 10 1607 and LTSB 2016.

Server editions follow their own support lifecycles, much longer than the desktop versions with the same build, so do not apply desktop end-of-support dates to servers.

Why Windows 11 says "version 10.0"

This confuses almost everyone once. Run ver on a Windows 11 PC and it says "Microsoft Windows [Version 10.0.26200...]". Some programs and websites report "Windows 10" on a Windows 11 PC for the same reason.

Microsoft kept the internal version number at 10.0 for Windows 11 to avoid breaking older software that checks it. The marketing name changed; the internal major version did not. The reliable way to tell them apart is the build: 22000 or higher means Windows 11, and anything lower is Windows 10. If a support person or a program insists you have Windows 10 because of "10.0", the build number settles it.

This is also why scripts should check the build, not the version string, when they need to treat Windows 11 differently.

Find the build number with Command Prompt and PowerShell

For scripts, remote support and machines where Settings will not open, these commands give the build directly.

:: Command Prompt
ver
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"
reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v DisplayVersion

# PowerShell
Get-ComputerInfo -Property OsName, OsDisplayVersion, OsBuildNumber
(Get-CimInstance Win32_OperatingSystem).BuildNumber
$k = Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion'
"$($k.DisplayVersion)  build $($k.CurrentBuild).$($k.UBR)"

The last PowerShell line prints exactly what winver shows, such as "25H2 build 26200.9457", and is the most useful one to keep in a script. Get-ComputerInfo gathers a lot of information and can take several seconds; the registry read is instant.

Older guides use wmic os get Caption, Version, BuildNumber. WMIC has been removed from current Windows 11, so that command now fails with "'wmic' is not recognized". The Get-CimInstance line above is the replacement, and our WMIC-to-PowerShell guide covers every other old WMIC command.

Match your build to a Windows update (KB number)

Every cumulative update is published with a KB number and the build revision it produces. Knowing that link helps when a guide says "this is fixed in KB5124008" and you want to know whether you have it.

1. Find your full build with winver, for example 26100.9457.
2. Open Settings > Windows Update > Update history and look at the newest entry under Quality updates. It shows the KB number of the last cumulative update you installed.
3. Compare with the update's release notes, which state the build it brings, such as "OS Builds 26100.9457 and 26200.9457".

If your revision is lower than the build named in a fix, you do not have that fix yet; install pending updates. Our write-ups of recent updates, such as the September 2026 update, list the builds each one produces.

Build vs version vs edition: what support teams actually want

When someone asks "what Windows do you have?", they usually need three separate facts, and it helps to give all three at once.

• Edition: Home, Pro, Enterprise or Education. It decides which features and policies exist. In Settings > About, it is the first line under Windows specifications.
• Version: 24H2, 25H2, 26H2 and so on. It decides which features you have and when support ends.
• OS build: 26200.9457, for example. It pins down the exact update level.

A complete answer sounds like "Windows 11 Pro, version 25H2, build 26200.9457". The winver window shows version and build; Settings > About shows all three. Some support teams also ask whether the system is 64-bit, also shown under Device specifications as System type, and our guide to 32-bit and 64-bit Windows explains that part.

A related trick: in Settings > About, the Copy button next to Windows specifications copies edition, version, install date, build and experience in one go, ready to paste into an email or chat with support.

Find the build of a Windows ISO or installation USB

Before installing or upgrading from media, it helps to check which build is on it, so you do not install an older version by mistake.

1. Double-click the ISO to mount it, or insert the USB drive, and note its drive letter, say D.
2. Open Command Prompt or Terminal and run:

   dism /Get-WimInfo /WimFile:D:\sources\install.wim /Index:1

   If the file is called install.esd instead, use that name.
3. Read the Version line, for example 10.0.26100, and the ServicePack Build, which is the revision.

Running the command without /Index:1 lists every edition in the image. Media from Microsoft's download page always carries a current build; old USB sticks from a drawer often do not, and installing from them means a long round of updates afterward.

Check another PC's build, or a whole office

For a family member's PC, Quick Assist plus winver is the simplest route. For many PCs, PowerShell remoting returns every build in one command:

Invoke-Command -ComputerName (Get-Content .\pcs.txt) -ScriptBlock {
  $k = Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion'
  [pscustomobject]@{ PC = $env:COMPUTERNAME; Version = $k.DisplayVersion; Build = "$($k.CurrentBuild).$($k.UBR)" }
} | Sort-Object Build | Format-Table PC, Version, Build

Sorting by build puts the machines most behind at the top. In Intune, the device list shows the OS version for every enrolled PC, and Windows Update reports show compliance by build. Before Patch Tuesday on October 13, 2026, it is worth running that report specifically for 26100 on Pro devices, because those are the ones leaving support.

Find the build when Windows will not start

If Windows will not boot, you can still find the build, which helps when choosing recovery media or asking for help.

From the recovery environment, open Troubleshoot > Advanced options > Command Prompt. The recovery environment runs its own copy of Windows, so ver there shows the recovery version, not necessarily yours. To read the installed Windows build, find which drive letter your Windows folder has in recovery (often D: rather than C:), then load its registry and read the values:

reg load HKLM\OFFSOFT D:\Windows\System32\config\SOFTWARE
reg query "HKLM\OFFSOFT\Microsoft\Windows NT\CurrentVersion" /v CurrentBuild
reg query "HKLM\OFFSOFT\Microsoft\Windows NT\CurrentVersion" /v UBR
reg unload HKLM\OFFSOFT

The UBR value is shown in hexadecimal; convert it with any calculator in programmer mode to get the familiar revision number. Unload the hive when finished.

Insider builds, and how to tell if you are on one

Windows Insider builds are previews of upcoming features. They use higher build numbers that change frequently, and Windows shows a watermark with the build number in the bottom-right corner of the desktop. To check, open Settings > Windows Update > Windows Insider Program: if you are enrolled, it shows the channel.

Insider builds are fine for testing on a spare PC and a poor idea on the only computer you rely on, because they can contain serious bugs. If you joined by accident, or a PC came to you already enrolled, choose to stop getting preview builds on that page. Depending on the channel, you may need to wait for the next public release or reinstall to return to a normal build.

For IT admins: build numbers in policy, reporting and compliance

Target versions, not builds. Use the Select the target Feature Update version policy (TargetReleaseVersion and TargetReleaseVersionInfo, such as 25H2) to hold or move devices between versions. Builds then advance automatically with monthly updates.

Compliance by revision. For security baselines, define the minimum acceptable revision per base build after each Patch Tuesday, for example "26200 must be at least revision X". Intune compliance policies support a minimum OS version check written in the full four-part format, such as 10.0.26200.9457.

Watch the 24H2 deadline. Pro and Home devices on 26100 drop out of support after the October 13, 2026 update. Enterprise and Education editions on 24H2 keep receiving updates until October 12, 2027, which is worth confirming per device; mixed editions in one fleet are common after hardware refreshes.

Windows build number: frequently asked questions

Ethan's aunt upgraded that weekend. Jake had shown her the Windows Update page, where 26H2 was waiting as a small download, and after one restart winver read "Version 26H2, OS Build 26300". She now knows the three words support desks want, edition, version and build, and where to find them in ten seconds. More usefully, she knows the build is not trivia. It is the date stamp on her computer's safety. Any time a headline says "Windows update fixes serious flaw", one winver tells her whether she has it.

Revision note. Written October 2, 2026, rewriting our 2016 guide with the current build table; it gets a dated line when the next version ships. Ten seconds with winver can save you an hour on a support call, and tell you at a glance whether your PC is still protected.