Do not delete files from C:\Windows\WinSxS yourself. This folder is the Windows component store, and removing files by hand can prevent Windows from starting or updating. To reclaim eligible space, use Windows Update Cleanup or DISM's component cleanup after checking what the store actually uses.
Check the real size before cleaning
File Explorer may make WinSxS look unusually large because many files are hard-linked to other Windows locations. Counting each link as another file overstates how much space that folder alone occupies. A large reported folder size therefore does not mean the same amount can be recovered. Do not use that number as a cleanup target.
First open File Explorer > This PC and record the free space on the Windows drive. Then open Start, type cmd, right-click Command Prompt, and select Run as administrator. In the elevated window, run:
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
Read the Actual Size of Component Store and Component Store Cleanup Recommended lines. The report also separates files shared with Windows from backups, disabled features, cache, and temporary data. Shared files are not spare copies you can simply erase. Microsoft's component store size guide explains why Explorer's total and DISM's actual size differ. Analysis does not remove anything, so you can run it before deciding whether cleanup is worthwhile.
If DISM says cleanup is not recommended, stop here unless you have a separate Windows Update problem to investigate. A different location may account for your full drive. For example, update downloads in C:\Windows\SoftwareDistribution\Download have a different purpose and cleanup path; see the Windows Update cache guide.
Use Windows Update Cleanup first
Complete any pending Windows update and restart when Windows asks. Cleaning during an installation makes it harder to tell whether the files you see are temporary or still needed. Check Start > Settings > Windows Update on Windows 11, or Start > Settings > Update & Security > Windows Update on Windows 10.
Open Start and search for Disk Cleanup. Select the Windows drive, usually C:, then choose Clean up system files and select the drive again. When the list appears, select Windows Update Cleanup if available. Review every other selected category: Downloads and Previous Windows installation(s) are separate decisions. Select OK > Delete Files and let Windows finish. This is the supported way to let Windows choose eligible system files; the category may be absent when there is nothing to remove.
The risk is losing the ability to uninstall some older updates whose replacement files are cleared. This cleanup has no ordinary file-by-file undo, and files removed by system cleanup do not go through the Recycle Bin. If you may need to roll back a recent update, postpone cleanup until you are comfortable keeping it. A restore point or backup made before servicing can provide a recovery route, but neither should be treated as a guaranteed way to restore individual component versions.
Recheck free space in File Explorer > This PC. A smaller-than-expected gain does not imply that Disk Cleanup missed the whole WinSxS folder. Some components are still required, and the folder's apparent size includes hard-linked files.
Use DISM when you need a direct component cleanup
If the DISM analysis recommends cleanup and Disk Cleanup leaves eligible component data, open an elevated Command Prompt as above. Run the standard command:
Dism.exe /Online /Cleanup-Image /StartComponentCleanup
Wait for DISM to finish; do not close the console or interrupt servicing to chase a percentage that appears to pause. This command removes superseded component versions without the scheduled task's grace period or one-hour limit. It does not delete the entire store. Microsoft's WinSxS cleanup instructions document this command and the alternatives.
The immediate deletion means an older replaced component may no longer be available for rolling back an update. There is no simple undo command to put those exact versions back. If update rollback matters today, let Windows perform its scheduled maintenance instead. On Windows 10 and 11, open Start, type Task Scheduler, then go to Task Scheduler Library > Microsoft > Windows > Servicing > StartComponentCleanup. You can right-click the task and choose Run, or simply leave automatic maintenance alone. Microsoft's documentation says its automatic run waits at least 30 days after an updated component is installed before removing the previous version; a manually started task also has a one-hour timeout.
When DISM completes, run the analysis command again and compare the report, then check free space in File Explorer. Do not assume the apparent WinSxS folder size will fall by the same amount. If DISM reports an error, copy the error code and investigate that servicing problem rather than deleting files from C:\Windows\WinSxS to force a result.
Leave ResetBase out of routine cleanup
You may see this stronger command suggested elsewhere:
Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase
Do not use it for routine free-space maintenance. Microsoft says /ResetBase removes all superseded versions in the component store and makes existing update packages impossible to uninstall after it completes. Future update packages can still be uninstalled, but the current rollback options are lost. There is no switch that reverses that decision. If you need the option to remove a recent update, use the standard cleanup or wait for maintenance instead.
Likewise, avoid taking ownership of WinSxS, deleting its subfolders, or using a generic duplicate-file cleaner on it. Hard links and servicing records make these approaches misleading. Moving WinSxS to another drive with a junction is also not a substitute for component servicing; Windows expects this system store in its managed location. If Windows remains short of space after the supported cleanup, inspect other large folders and move ordinary data rather than altering the component store.
Reviewing cleanup with AiCleanDisk Pro
AiCleanDisk Pro includes system optimization items and DISM-type operations among its cleanup categories. It shows a risk level and a confirmation dialog before cleaning, and the dialog says when a system-command operation skips the Recycle Bin. Scanning the system drive and auto clean outside the AI category are free; AI auto-clean items, scanning other drives, and folder moving require a license. Review the selected item and its rollback limits before confirming, just as you would with DISM directly. The AiCleanDisk Pro home page has the current Windows app details.
Keep the component store in perspective
WinSxS grows as Windows receives updates, and Windows already performs component cleanup in the background. Measure free space, use DISM's actual-size report, and let the supported tools decide what is removable. If cleanup does not recover enough space, look for a different source of growth instead of repeating stronger WinSxS commands.