How Much Free Space Does Windows 11 Need? Install, Updates & How to Free It

Windows 11 needs a drive of at least 64 GB to install, and Windows 10 at least 32 GB. Those are minimums for the drive, not free space. In practice, keep at least 20 to 30 GB free before a feature update, at least 10 GB free for monthly updates, and ideally 15 to 20 percent of the drive free at all times so Windows and your SSD stay fast. Check free space in Settings > System > Storage. If you are short, run Cleanup recommendations there, delete temporary files and the Windows.old folder, and move photos and videos to OneDrive or an external drive. During an update, Windows can also borrow an external drive for temporary files.

Ethan's mother has a small laptop with a 64 GB drive, and every few months it showed the same message: "Windows needs space to update." She had already deleted most of her photos, and the update still failed. Ethan brought it to Jake's shop. Jake opened Storage settings and found the real culprits in two minutes: a 9 GB Windows.old folder from the last upgrade, 5 GB of temporary update files, a hibernation file sized for a laptop she never hibernated, and a Downloads folder full of installers she had used once. Twenty minutes later the laptop had 22 GB free, the update installed, and her photos came back from OneDrive. This page explains how much space Windows really needs, where it goes, and how to get it back.

Figures on this page are practical targets for a typical PC. A PC with lots of apps, large games or a big hibernation file will need more headroom than the minimums suggest.

How much space Windows needs to install

A fresh Windows 11 installation typically uses between 20 and 30 GB once it settles, before your apps and files. The 64 GB minimum exists because Windows needs room to grow: updates, reserved storage, the page file, the hibernation file and the temporary files every upgrade creates. A drive that barely meets the minimum will install Windows, but it will struggle with every update afterwards.

That is why Ethan's mother's laptop kept failing. 64 GB was enough to run Windows 11, but not enough to run it plus a few apps, a year of updates and an old upgrade's leftovers.

Why Windows needs so much more than its own size

Windows does not just store its own files. While running, it keeps several large system files and temporary areas on the system drive. Some of them are fixed, some grow and shrink, and some are left behind after updates until something cleans them up. Understanding them is the key to freeing space safely, because most of what fills a small drive is not your documents.

• Reserved storage: about 7 GB set aside on many PCs so updates always have room to install.
• Page file (pagefile.sys): virtual memory, often several GB, managed automatically.
• Hibernation file (hiberfil.sys): a copy of memory for hibernate and Fast Startup, often 40 percent of your RAM.
• Component store (WinSxS): Windows' own components and older versions kept so updates can be uninstalled.
• Update downloads: files waiting in the update cache and Delivery Optimization.
• Windows.old: your previous Windows after an upgrade, kept for ten days so you can go back.
• Temporary files: left by apps, installers and browsers.

On a 512 GB drive none of this matters much. On a 64 or 128 GB drive, these items can together take a third of the space.

Sizes vary from PC to PC; the point of the table is to show which items you can shrink and which you should leave to Windows.

Check how much free space you have

1. Open Settings with Windows + I.
2. Go to System > Storage.
3. Look at the bar for your system drive, usually C:, which shows used and free space.
4. Select Show more categories to see Apps, Temporary files, System and reserved, Documents, Pictures and more.
5. Select any category to see what is inside and remove what you do not need.

For a quick look without Settings, open File Explorer and select This PC; each drive shows a bar with free space underneath. Our guide to checking your drive capacity shows more ways, including Disk Management and the command line.

The bar turns red when the drive is nearly full, and Windows shows a low disk space notification when free space falls very low. Our page on the low disk space warning explains what triggers it and why it is better to act on it than to hide it.

Check before every big update, not only when something fails. A ten-second look at the Storage bar tells you whether the next upgrade will go smoothly.

How much space updates need

Windows updates come in two kinds, and they need very different amounts of space.

Monthly cumulative updates, released on the second Tuesday of each month, include all security and quality fixes. They download a few hundred megabytes to a couple of gigabytes, but installing them needs extra room to unpack and stage files. Keeping at least 10 GB free means they will rarely fail for lack of space.

Yearly feature updates vary. Some are delivered as a small enablement package that switches on features already present, such as the move from Windows 11 version 24H2 to 25H2, which installs much like a monthly update. Others are a full new version of Windows, such as the move from 23H2 to 24H2, or from Windows 10 to Windows 11. Those full upgrades download several gigabytes, unpack them, keep your old Windows as Windows.old, and need far more room: plan on 20 to 30 GB free.

When there is not enough room, Windows Update says "Windows needs space to update" or an update fails with error 0x80070070, which means the disk is full. Freeing space and retrying fixes both. Our guide to a Windows 11 update that failed to install covers other causes if space was not the problem.

Reserved storage: the 7 GB Windows keeps for updates

Since Windows 10 version 1903, many PCs set aside about 7 GB of reserved storage. Apps and temporary files can use that space day to day, but when an update arrives, Windows clears it so the update has room. The aim is to stop updates failing on nearly full drives. The amount changes with installed optional features and languages.

To see whether your PC uses it, open Command Prompt as administrator and run DISM /Online /Get-ReservedStorageState. You can turn it off with DISM /Online /Set-ReservedStorageState /State:Disabled, but on a small drive that usually makes updates more likely to fail, not less. Leave it on unless an expert has a specific reason.

In Settings, reserved storage appears inside System & reserved under Storage. It is one of the reasons that category looks large on small drives.

If you see a large "System & reserved" figure on a new laptop with very little installed, reserved storage is usually most of the explanation, and that space will be used for the next update rather than lost.

Free up space fast: the safe order

1. Cleanup recommendations: in Settings > System > Storage, open Cleanup recommendations. It lists temporary files, large or unused files, files synced to the cloud and unused apps, and lets you remove them in one place.
2. Temporary files: in the same Storage page, select Temporary files, check Windows Update Cleanup, Delivery Optimization files, Temporary files and Thumbnails, and select Remove files. Leave Downloads unchecked until you have looked inside it.
3. Previous Windows installation: if you upgraded more than a few days ago and everything works, remove Previous Windows installation(s) from the same list. Our guide to deleting the Windows.old folder explains the trade-off.
4. Downloads folder: sort by size and delete old installers, ISO files and archives you no longer need.
5. Recycle Bin: empty it.
6. Unused apps and games: uninstall from Settings > Apps > Installed apps, sorted by size.
7. Photos and videos: move them to OneDrive with Files On-Demand, or to an external drive.

Most PCs gain 10 to 30 GB from these seven steps without touching anything risky. Our guide to deleting temp files safely covers the Temp folders by hand if you prefer.

Tame the Downloads folder

The Downloads folder is where space disappears quietly. Every installer, PDF, ZIP file and video you download lands there, and few people ever empty it. Open it, switch to Details view, and sort by Size: installers for programs you have already installed, ISO files and old archives are usually safe to delete. Move anything worth keeping, such as receipts and documents, to Documents or OneDrive.

Then change the habit: either empty Downloads monthly, or let Storage Sense delete files there that have not been opened for 60 days. If you want downloads saved somewhere else entirely, our guide to changing the download location shows how to move the folder to another drive.

Language packs and optional features

Extra display languages, speech packs, handwriting packs and optional features take space and also make updates larger, because each one is updated with Windows. Open Settings > Time & language > Language & region and remove languages you do not use, and check Settings > System > Optional features for features you added once and no longer need. Removing them saves a few hundred megabytes to a few gigabytes, and it trims future updates too.

Keep the languages you actually type or read in, and keep any optional feature that a program you use depends on, such as a legacy component a business app needs. When unsure, leave it; the savings from any single feature are modest.

Turn on Storage Sense so it stays clean

Storage Sense cleans up automatically. Turn it on in Settings > System > Storage, then select Storage Sense to set how it behaves: run it every day, week or month, or only when disk space is low; empty the Recycle Bin after a set number of days; delete files in Downloads that have not been opened for a set time; and make OneDrive files online-only after a period without use.

For small drives, set it to run when disk space is low and to empty the Recycle Bin after 30 days. Be careful with the Downloads option: if you keep files there long term, set it to Never or you may lose them. Storage Sense never deletes your documents or photos outside Downloads; with OneDrive, it only removes local copies of files that remain safe in the cloud.

Delivery Optimization and its cache

Delivery Optimization lets Windows share update pieces between PCs on your network, and optionally the internet, so updates download faster and use less bandwidth. It keeps a cache of those pieces on the system drive, usually cleared automatically, but it can grow to several gigabytes after big updates. Clear it with the Delivery Optimization files option in Temporary files or Disk Cleanup.

To control it, open Settings > Windows Update > Advanced options > Delivery Optimization. Turning off Allow downloads from other devices stops sharing; under Advanced options on the same page you can limit bandwidth. On a single home PC, sharing with devices on your local network is harmless and can help if you have several PCs.

Shrink or remove the hibernation file

The hibernation file, hiberfil.sys, holds a copy of memory so the PC can hibernate and so Fast Startup can work. By default it is often around 40 percent of installed RAM, so a laptop with 16 GB of memory may have a hibernation file of about 6 GB. If you never use hibernate, you have two options, both run from Command Prompt as administrator:

• powercfg /h /type reduced shrinks the file to roughly half its size. Fast Startup still works; full hibernate does not.
• powercfg /h off removes the file completely. Hibernate and Fast Startup both stop working.

To turn it back on later, run powercfg /h on. On laptops you carry around, hibernation protects work when the battery runs out, so on those consider the reduced size rather than turning it off. Our guide to sleep, hibernate and powercfg explains the power options in detail.

The page file: leave it alone, usually

The page file, pagefile.sys, is space Windows uses as overflow memory. Windows manages its size automatically, and on most PCs it is a few gigabytes. Guides that suggest deleting or shrinking it to free space are risky: with too small a page file, apps can crash when memory runs short, and Windows cannot save crash information for troubleshooting.

If the page file is unusually large, for example tens of gigabytes after a memory-heavy session, a restart usually lets Windows shrink it again. If you have a second drive, you can move the page file there in System Properties > Advanced > Performance Settings > Advanced > Virtual memory, but keep a small one on C: so crash dumps still work.

System Restore points

System Restore keeps restore points on the drive, and over time they can use a few percent of the space. To see and control it, search for Create a restore point, select drive C:, and choose Configure. The Max Usage slider sets the limit; on a small drive, a few gigabytes is enough to keep recent restore points. Delete removes all restore points for that drive, which frees space but leaves you without a way back if the next change goes wrong. A balanced approach is to lower the limit rather than delete everything.

Clean the component store (WinSxS)

The WinSxS folder in C:\Windows looks huge in File Explorer, often 8 to 15 GB, but much of that is an illusion: many of its files are shared with other Windows folders through hard links, so they are counted twice. You must never delete files from it by hand; doing so breaks Windows.

To clean it safely, open Command Prompt as administrator and run DISM /Online /Cleanup-Image /StartComponentCleanup. It removes superseded versions of components that are no longer needed, often freeing one to several gigabytes. Windows also does this automatically in the background through a scheduled task. Adding /ResetBase frees a little more but means you can no longer uninstall installed updates, so use it only on a PC that is working well after updates.

The Windows Update Cleanup option in Temporary files and Disk Cleanup does a similar job with less typing.

Disk Cleanup still works

The classic Disk Cleanup tool is still in Windows 11. Press Windows + R, type cleanmgr and press Enter, choose drive C:, then select Clean up system files to include Windows Update Cleanup, previous Windows installations, Delivery Optimization files and old device driver packages. Check what you want removed and select OK.

Microsoft has moved most of its features into Settings, and Disk Cleanup may be retired in a future version, but for now it remains a fast way to see the size of each category in one window.

Disk Cleanup and the Settings page remove the same kinds of files, so there is no need to run both on the same day; use whichever you find easier to read.

Compact OS for very small drives

On drives of 64 GB or less, Compact OS compresses Windows' own system files, often freeing a couple of gigabytes or more. Windows may enable it automatically on very small devices. To check, run compact /compactos:query in Command Prompt as administrator. To turn it on, run compact /compactos:always; it takes several minutes. On modern processors the speed cost is small. It is a good option for budget laptops with soldered 64 GB storage, which cannot be upgraded.

Do not compress the whole drive with NTFS compression from drive properties; that slows everything and gives less benefit than Compact OS for the system files.

If you later move to a larger drive, you can turn Compact OS off with compact /compactos:never, which decompresses the system files again; make sure there are a few gigabytes free first, because the uncompressed files need the room back.

Not enough space for an update? Use an external drive

When a feature update needs more room than the PC has, Windows Update can use an external drive or USB stick for temporary files during the upgrade. When you see "Windows needs space to update", follow the prompts, connect a USB drive with plenty of free space, typically 10 GB or more, select it, and continue. Keep it connected until the update finishes, then you can remove it.

This is especially useful on laptops with 64 GB of storage that cannot be expanded. The drive is only used for temporary files; your files and the updated Windows stay on the internal drive.

Space checklist before upgrading Windows 10 to 11

1. Check that your drive is at least 64 GB and that the PC meets the other Windows 11 requirements; our guide to the Windows 11 requirement checks covers each one.
2. Back up your files to OneDrive or an external drive.
3. Run Cleanup recommendations and Temporary files cleanup.
4. Remove any old Windows.old folder from a previous upgrade.
5. Uninstall apps and games you no longer use.
6. Aim for at least 20 GB free, ideally 30 GB.
7. Keep a USB drive with 10 GB or more free nearby in case Windows asks for extra room.
8. Start the upgrade from Windows Update, and leave the PC plugged in until it finishes.

After the upgrade, keep Windows.old for a week or so while you check that everything works, then remove it to get the space back.

Find the biggest space users

Settings shows categories, but sometimes you need to know which exact folders are large. In Settings > System > Storage, select Show more categories and then Other to see large folders that do not fit a category. In File Explorer, open a folder, switch to Details view and sort by Size for files, though folders do not show sizes there. Our guide to finding what is eating your storage shows how to track down large folders without extra software.

The usual suspects are game libraries, video projects, virtual machine disks, phone backups made by iTunes or other apps, and old installers in Downloads. Games alone can take 100 GB each today.

Games and launchers

Modern games are often 50 to 150 GB each, and updates can need as much free space again while they install. Game launchers such as Steam, the Xbox app and Epic let you move installed games to another drive and set a default library on a larger drive. If your system drive is small, put games elsewhere from the start. Uninstalling a game you finished is usually safe: your saves are often synced to the cloud by the launcher, though check the game's own cloud save setting before you remove it.

Before uninstalling a large game you might replay, check whether the launcher lets you back up or move the game files to an external drive instead; restoring from a local copy is much faster than downloading 100 GB again.

Hidden space users people miss

• Phone backups: iTunes or the Apple Devices app store iPhone backups in your user folder, often tens of gigabytes.
• Browser caches: each browser keeps a cache that can reach a few gigabytes; clear it from the browser's privacy settings.
• Virtual machine disks: VirtualBox, Hyper-V and WSL store virtual disks that grow over time.
• Video and photo editor caches: preview and proxy files left behind after projects.
• Installer caches: Office, Adobe and driver installers sometimes keep their setup files.
• Old device drivers: previous driver packages, removable with Disk Cleanup's Device driver packages option.
• Duplicate photos: the same pictures imported several times from phones and cameras.

Check these with the Storage page's Other category or by looking at folder sizes in your user folder.

On the shop's busiest day, Jake found a 40 GB iPhone backup on a laptop whose owner had sold the phone two years earlier. Backups for devices you no longer own are among the safest large deletions on any PC.

Use OneDrive Files On-Demand

With OneDrive, Files On-Demand keeps your files visible in File Explorer while storing them in the cloud until you open them. Right-click a folder you rarely use and choose Free up space; the files stay listed with a cloud icon but no longer take space on your drive. Open one, and it downloads. Storage Sense can do this automatically for files you have not opened in a set time.

The free OneDrive plan includes 5 GB, so large photo libraries need a Microsoft 365 plan or another storage option. Our guide to finding and opening OneDrive covers checking that it is syncing before you free up space.

Before freeing up space, confirm that OneDrive shows a green check or cloud icon on the folder, which means the files are uploaded. Never delete files from the OneDrive folder to save space; deleting removes them from the cloud too. Free up space is the option that keeps them safe.

Move apps and folders to another drive

If your PC has a second drive or an SD card slot, you can move data off C:. In Settings > System > Storage > Advanced storage settings > Where new content is saved, choose another drive for new apps, documents, music, photos and videos. Many Store apps can also be moved from Settings > Apps > Installed apps by selecting the app and choosing Move. Desktop programs generally need uninstalling and reinstalling to a new location, and game launchers usually have their own option to add a library on another drive.

Personal folders such as Documents and Pictures can be moved too: right-click the folder, choose Properties > Location, and select a folder on the other drive.

On laptops with an SD card slot, a fast card set as the location for new photos, videos and music frees the internal drive without affecting apps. Choose a card rated for sustained writes if you plan to store video on it.

Why free space matters for SSD speed

Solid-state drives slow down when they are nearly full, because they need free blocks to write efficiently and to spread wear evenly. Keeping 15 to 20 percent of an SSD free keeps it fast and helps it last. On hard drives, a nearly full disk causes more fragmentation and slower file access. In both cases, a PC that has been "slow lately" sometimes just needs space.

Windows also needs free space for its own work: updates, the page file growing under load, the hibernation file and app caches. When the drive is full, these fail first, which shows up as crashes, failed updates and apps that will not open.

For IT: storage and updates at scale

Organizations with many small-drive devices usually handle space centrally. Microsoft Intune and other management tools can report free disk space per device, run cleanup scripts, and target feature updates only at devices with enough room. Windows Update for Business and Windows Autopatch both report devices that failed updates because of low space, which is often the first sign a fleet of older laptops needs attention. For thin clients and kiosks, LTSC editions and Compact OS keep the footprint small.

A simple rule used by many IT teams is to flag any device under 20 GB free before a feature update window and clean it up, or exclude it from that wave, rather than letting the update fail and roll back.

Living with a 64 GB or 128 GB laptop

• Keep Storage Sense on, running when space is low.
• Store photos, videos and music in OneDrive or on a microSD card if there is a slot.
• Prefer web apps and lightweight apps over large desktop suites where you can.
• Turn on Compact OS and use the reduced hibernation file.
• Remove Windows.old after every major upgrade once you are sure everything works.
• Keep a USB drive handy for feature updates.
• Check free space once a month.

With these habits, a 64 GB laptop stays usable for browsing, email and Office. For anything more, 256 GB is the practical minimum today when buying a new PC.

For Windows 10 PCs still receiving Extended Security Updates, the same advice applies: monthly ESU updates need a few gigabytes of room, and Storage Sense, Disk Cleanup and the cleanup steps above all work the same way on Windows 10. The Settings paths differ slightly, with Storage under Settings > System > Storage and Cleanup recommendations missing from older versions.

What Jake removed from the 64 GB laptop

1. Previous Windows installation (Windows.old): about 9 GB.
2. Windows Update Cleanup and Delivery Optimization files: about 5 GB.
3. Hibernation file reduced with powercfg: about 2 GB.
4. Old installers and archives in Downloads: about 3 GB.
5. Recycle Bin and temporary files: about 1.5 GB.
6. Photos set to online-only with OneDrive: the rest, bringing free space to 22 GB.

Nothing on that list was a document or photo she lost. It was all space Windows and apps had used and no longer needed, which is typical of what a small drive gives back.

A five-minute monthly storage routine

Once a month, open Settings > System > Storage and glance at the bar. If free space is below 20 percent, open Cleanup recommendations and accept the temporary files it suggests. Look at Downloads and the Recycle Bin. After any big Windows update, check whether a previous installation is listed and remove it once you are happy. That is all most PCs need; with Storage Sense on, many months there will be nothing to do.

Put a reminder in your calendar for the first weekend of each month, or tie it to Patch Tuesday, the second Tuesday, when monthly updates arrive. A PC that is checked monthly almost never sees "Windows needs space to update" again, because the space problem is caught long before an update needs the room.

Check free space from the command line

For quick checks or scripts, open PowerShell and run Get-PSDrive C to see used and free space in bytes, or Command Prompt and run fsutil volume diskfree C:, which reports free bytes in a readable form. For every drive at once in PowerShell, run Get-Volume. These are handy when helping someone over the phone, because the numbers are easy to read out.

For a folder-by-folder view without extra software, PowerShell can total a folder: (Get-ChildItem $env:USERPROFILE\Downloads -Recurse -File | Measure-Object Length -Sum).Sum / 1GB shows the size of your Downloads folder in gigabytes. Change the path to check any other folder.

When cleaning is not enough: a bigger drive

If your PC has an M.2 slot or a 2.5-inch bay, replacing a small drive is often the best long-term fix. A 512 GB or 1 TB SSD costs far less than it did a few years ago. You can clone the old drive to the new one with the drive maker's tool, or install Windows fresh and restore your files from backup; your Windows license reactivates automatically on the same PC. Many budget laptops with 64 GB of storage have it soldered to the board, though, which rules this out; check the model's specifications before buying a drive.

An external SSD is the alternative for those laptops: fast enough for photos, videos and even some games, and easy to carry.

A clean install as the last resort

A PC that has been upgraded several times can carry years of leftovers. If cleanup still leaves too little space, back up your files and use Settings > System > Recovery > Reset this PC with Remove everything, or a clean install from installation media. A fresh Windows 11 installation is lean, and you reinstall only the apps you still use. It takes an afternoon, but it is often the fix that lets a small-drive laptop keep updating for years more.

Before you reset, note your installed apps, export browser bookmarks and passwords, and make sure your files are backed up in at least one place outside the PC, such as OneDrive or an external drive.

Error messages that mean low space

• "Windows needs space to update": free space or use an external drive during the update.
• 0x80070070: not enough space on the disk.
• "There is not enough space on the disk": while copying or installing; free space first.
• "Low Disk Space" notification: the drive is nearly full.
• Apps failing to open or save: a full drive can cause both.
• Update rollback with "undoing changes": sometimes caused by low space during installation.

Not every update error is about space. If you have plenty free and updates still fail, the cause is elsewhere; our guide to update error 0x800f0922 covers a related problem with the small system reserved partition, which is a different kind of space shortage.

Myths and risky cleanup advice

• "Registry cleaners free space." The registry is small; cleaning it saves almost nothing and can break apps.
• "Delete files from C:\Windows by hand." Removing system files, including from WinSxS or Installer folders, can stop Windows from updating or starting.
• "Third-party cleaners find more." Most find the same temporary files as Storage Sense; some bundle adware or delete browser data you wanted.
• "Turn off the page file to save space." It causes crashes when memory runs short.
• "Disable reserved storage for 7 GB free." On small drives it is what keeps updates working.
• "Delete the SoftwareDistribution folder regularly." It is a repair step for broken updates, not routine cleanup; Windows Update Cleanup does the routine job.

The built-in tools on this page are safe because Windows knows which of its own files are still needed. Hand deletion and aggressive cleaners do not.

What this page said in 2016

When this page was first written in 2016, the question was how much free space a Windows 7 or 8.1 PC needed to take the free upgrade to Windows 10. The answer then was 16 GB for 32-bit and 20 GB for 64-bit Windows 10. In 2019, Microsoft raised the minimum to 32 GB for all versions, alongside reserved storage. Windows 11 doubled it again to 64 GB. Each time, the reason was the same: updates need room, and too many small drives were failing them.

The same pattern explains today's advice to keep 20 to 30 GB free. Minimums tell you whether Windows will install; free space tells you whether it will keep updating.

Free space for Windows: frequently asked questions

Ethan's mother has not seen "Windows needs space to update" since. Storage Sense empties her Recycle Bin every month, her photos live in OneDrive, and a small USB drive sits in her laptop bag for the next big upgrade. The lesson from Jake's shop was simple: Windows does not need much room to run, but it needs room to change, and most of the space it wants back is space it filled itself.

Revision note. Written October 2, 2026, rewriting our 2016 Windows 10 upgrade space note into a complete guide to how much free space Windows 11 and 10 need and how to get it. May your drive always have room to grow.