# How to Delete Windows Update Files Without Losing Rollback "Windows Update files" is not one folder. On a typical PC it means four separate piles: superseded update components inside the component store, the download cache in `C:\Windows\SoftwareDistribution\Download`, the previous installation in `C:\Windows.old` after a feature update, and the Delivery Optimization cache that shares updates with other PCs. Each one is removed through a different Windows tool, and each one costs something different, from nothing at all to the ability to go back to your previous version of Windows. The short answer: use Disk Cleanup or Settings for the space, keep `SoftwareDistribution` for repairing a stuck update rather than for saving space, and only remove `Windows.old` once the new version has proven itself. ## Four places, four different costs | Location | What it holds | Remove it with | What you give up | | --- | --- | --- | --- | | Windows Update Cleanup | Older versions of updated components in the component store | Disk Cleanup, Clean up system files | Earlier rollback of those components | | `SoftwareDistribution\Download` | Update packages Windows Update downloaded | Microsoft's reset steps, service stopped first | Pending downloads are fetched again | | `Windows.old` | The Windows installation before an upgrade | Settings, Temporary files | The Go back option in Recovery | | Delivery Optimization cache | Update and Store downloads kept for sharing | Disk Cleanup or the cache clears itself | Peers on your network fetch from the internet instead |
Update files have different costs
Four kinds of update files sit in different places, are removed by different Windows tools and give up different things.
## Measure before you delete anything Open Settings › System › Storage and select Temporary files. Windows lists categories with their sizes, which tells you whether update files are worth your time at all. A drive that is full because of a game library or a video project will not be saved by a few hundred megabytes of update cache. For the component store, the number File Explorer shows for `C:\Windows\WinSxS` is misleading because of hard links. The [WinSxS cleanup article](/windows/blog/winsxs-folder-cleanup-windows) shows how to measure the real overhead with DISM before you clean it, so it is not repeated here. ## Windows Update Cleanup in Disk Cleanup This is the safest of the four and usually the first one to try. 1. Search for Disk Cleanup from the taskbar and open it. 2. Choose the system drive and select OK. 3. Select Clean up system files, choose the drive again and select OK. 4. Tick Windows Update Cleanup, select OK, then Delete files. [Microsoft's component store guide](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/clean-up-the-winsxs-folder) says this option reduces the size of the component store. Windows already does a version of this on a schedule: it keeps previous versions of some components for a period of time so you can roll back, then removes them automatically. Running the cleanup yourself only brings that forward. The cost is that rollback window. Right after a large cumulative update, while you are still checking that printers, drivers and your main apps behave, wait a few days before running it. The more aggressive DISM switch, `/ResetBase`, makes every installed update permanent and is covered in the WinSxS article; Disk Cleanup does not need it. ## SoftwareDistribution\Download is for repairs, not space `C:\Windows\SoftwareDistribution\Download` is where Windows Update keeps the packages it downloaded. Windows manages it during normal updates, and the folder is usually not where large amounts of space hide. Clearing it is a repair step for updates that keep failing to download or install, which is how Microsoft presents it. [Microsoft's reset instructions](https://learn.microsoft.com/en-us/troubleshoot/windows-client/installing-updates-features-roles/additional-resources-for-windows-update) first point to the Windows Update troubleshooter. When that is not enough, the manual steps stop the services that hold these files, so nothing is being written while you work on the folder. From an elevated Command Prompt: ```cmd net stop bits net stop wuauserv net stop cryptsvc ``` Microsoft's article then renames the folders rather than deleting them, and it asks you to do this only if the earlier steps of the reset did not help: ```cmd Ren %Systemroot%\SoftwareDistribution\DataStore DataStore.bak Ren %Systemroot%\SoftwareDistribution\Download Download.bak Ren %Systemroot%\System32\catroot2 catroot2.bak ``` Start the services again when you are done: ```cmd net start bits net start wuauserv net start cryptsvc ``` Renaming keeps the old content until you know updates work again; Windows Update creates fresh folders and downloads what it still needs. Once Settings › Windows Update installs successfully, the `.bak` folders can go. The article also has a shorter "if all else fails" form that removes the whole `SoftwareDistribution` folder, including `DataStore`, not just the downloads. Treat it as the last step it is described as. Deleting the folder while Windows Update is running is the version to avoid: files in use stay behind, and a download in progress can break halfway. Mole for Windows has a narrower version of this repair under Optimize, called Reset stuck update downloads. It is offered only when the same update has failed to install at least twice in a row within the last 30 days, never while Windows is installing an update or waiting for a restart, and at most once every 30 days. It stops Windows Update and BITS, empties only the `Download` folder and starts again whichever of the two services was running. It does not touch `DataStore`, `catroot2`, update settings or policies. ## Windows.old and the 10-day window After an upgrade or a feature update, the previous installation sits in `C:\Windows.old`. It is what makes Settings › System › Recovery › Go back possible. [Microsoft's rollback page](https://support.microsoft.com/windows/deployment/install-upgrade/go-back-to-the-previous-version-of-windows) says that in most cases you have 10 days, and that going back needs the `windows.old` and `$windows.~bt` folders kept, user accounts added after the upgrade removed, and the USB drive you upgraded from, if you used one. Going back keeps personal files but removes apps and drivers installed after the upgrade. You often do not need to delete it at all. [Microsoft's deletion page](https://support.microsoft.com/en-us/windows/deployment/install-upgrade/delete-your-previous-version-of-windows) says the previous version is deleted automatically ten days after the upgrade. To remove it sooner, go to Settings › System › Storage › Temporary files, tick Previous version of Windows and select Remove files. The same page warns that this cannot be undone. Before you do, check the things that would make you want to go back: the apps you rely on start, the printer prints, the VPN connects and the files you care about are in your user folders rather than only inside `Windows.old`. A backup of your documents is not a substitute for this check, because Go back restores the system, not your files. ## The Delivery Optimization cache Delivery Optimization lets a PC download Windows and Store updates from other PCs on the local network, or the internet if you allow it, and share what it downloaded in return. [Microsoft's Delivery Optimization page](https://support.microsoft.com/en-us/windows/deployment/updates-lifecycle/delivery-optimization-in-windows) says the cache clears itself after a short time or when it takes up too much space, and that you can clear it sooner in Disk Cleanup by ticking Delivery Optimization Files. The [Delivery Optimization reference](https://learn.microsoft.com/en-us/windows/deployment/do/waas-delivery-optimization-reference) gives the defaults behind "a short time": a file is kept for up to three days, and the cache may use up to 20% of available drive space. Removing it costs little: Windows Update installs from its own download, and other PCs fetch from Microsoft instead of from you. To change whether this PC shares at all, go to Settings › Windows Update › Advanced options › Delivery Optimization. Mole's Clean page lists this cache as Delivery Optimization files. Mole asks the Delivery Optimization service itself to delete finished files, skips anything still downloading and anything pinned, and never takes ownership of the service's folder. ## Check the result - Run Disk Cleanup or Temporary files again and compare the categories with what you saw before. - Open Settings › Windows Update and select Check for updates. It should search and install normally. - Open Settings › System › Recovery. If Go back is gone, that is expected after removing `Windows.old`; if you still needed it, it cannot be brought back. ## What not to do - Do not delete files from `WinSxS` by hand or take ownership from TrustedInstaller to force it. - Do not delete `SoftwareDistribution` while the Windows Update service is running, and do not use it as routine space cleanup. - Do not remove `Windows.old` in the first days after an upgrade just because it is large. - Do not disable the Windows Update or BITS services to stop these folders from growing; that stops security updates too. For everything else that fills drive C:, continue with [sorting out a full C: drive](/windows/blog/windows-c-drive-full) or [finding large files](/windows/blog/find-large-files-on-windows). ## FAQ ### Is it safe to delete Windows Update files? Yes, when you use Windows' own tools: Windows Update Cleanup and Delivery Optimization Files in Disk Cleanup, and Previous version of Windows in Temporary files. The costs are an earlier end to component rollback and, for `Windows.old`, the end of the Go back option. ### Can I delete the SoftwareDistribution folder? Only as a repair for updates that keep failing, and only after stopping the Windows Update service. Microsoft's steps rename `Download` and `DataStore` instead of deleting them, so you can remove the renamed copies once updates work again. ### How long does Windows.old stay on my PC? In most cases 10 days after the upgrade. Windows then deletes it automatically, and the Go back option disappears with it. ### Will deleting Delivery Optimization files stop updates from working? No. They are copies kept for sharing with other PCs. Windows Update downloads from Microsoft when it needs a file again, and the cache also clears itself after a few days. Canonical: https://mole.fit/windows/blog/delete-windows-update-files