What is the WinSxS folder?
WinSxS is Windows' component store. It holds the files Windows is built from, including older versions after updates. Windows needs it to install updates, turn features on and off and repair damaged system files.
Never delete files in WinSxS by hand. It can stop updates and repairs from working and, at worst, stop Windows from starting. Safer ways to make room quickly are in free up disk space.
Why WinSxS looks bigger than it is
Many files in WinSxS are also visible in C:\Windows\System32 and other folders through hard links. File Explorer counts them twice. This command in an administrator terminal shows the real size:
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
Look for the actual size of the component store and the line saying whether a cleanup is recommended (Microsoft: Determine the actual size).
Clean up WinSxS with DISM
- Right-click Start → Terminal (Admin).
- Enter this command and press Enter:
Dism.exe /Online /Cleanup-Image /StartComponentCleanup
This removes superseded component versions that are no longer needed. It takes a few minutes, depending on the PC. Windows also runs this step itself as a scheduled task, but not always promptly. Microsoft documents both commands in Clean up the WinSxS folder.
More space with /ResetBase
Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase
This removes all superseded versions. Afterwards, installed updates can no longer be uninstalled. Only use it when your system is stable.
Alternative: Disk Cleanup
In Disk Cleanup, the Windows Update Cleanup option (under Clean up system files) does largely the same as the component cleanup.
Clean up WinSxS with DiskDetox
DiskDetox offers the cleanup of superseded Windows components in its optional Windows clean-up. It uses exactly the Windows tools above, with a single administrator confirmation, and explains first what happens: only old copies in the component store are removed; the folder itself stays. In the same pass you can remove Windows.old and the Delivery Optimization cache.
Windows clean-up with DiskDetoxComponent store, Windows.old and update leftovers, with one admin prompt.
Frequently asked questions
How big should WinSxS be?
There's no fixed limit. If File Explorer shows a very large number, it's usually the double-counted hard links. The AnalyzeComponentStore figure is the one that counts.
Can I move WinSxS to another drive?
No. The folder has to stay in C:\Windows. Moving or linking it breaks Windows.
Does “sfc /scannow” shrink it?
No. sfc /scannow checks and repairs system files; it doesn't free any space.