WinSxS folder
Also known as: component store, Windows side-by-side, WinSxS cleanup
WinSxS (the component store) is the Windows folder that holds the files needed to install, update, and roll back system features. It looks huge because of shared hard links, but its real size is smaller — and you must never delete it manually.
- The Windows component store at C:\Windows\WinSxS
- Reported size is inflated by hard links
- Clean only via Disk Cleanup or DISM, never manually
Why WinSxS looks so big
Located at C:\Windows\WinSxS, this folder stores every Windows component and update so features can be added, repaired, or rolled back. File Explorer overcounts it: many of its files are hard links that also appear elsewhere in Windows, so the reported size is far larger than the space it actually uses.
It does grow real bloat over time as superseded update components accumulate, which is what Windows Update cleanup targets.
The only safe way to shrink it
Never delete files inside WinSxS by hand — it will corrupt Windows. Instead, run Disk Cleanup and check Windows Update Cleanup, or use an elevated Command Prompt: DISM /Online /Cleanup-Image /StartComponentCleanup. These remove only the components Windows confirms are no longer needed.
How big should WinSxS be?
To see the truth behind Explorer’s inflated number, run DISM /Online /Cleanup-Image /AnalyzeComponentStore in an elevated Command Prompt. It reports the actual size of the component store, how much of it is shared with Windows through hard links, and whether cleanup is recommended.
A component store in the range of 5-10 GB of actual size is normal on an installation that has been through years of updates. If the analysis says cleanup is recommended, run StartComponentCleanup as above; adding /ResetBase frees more space but removes the ability to uninstall the updates already installed, so use it only when you are sure the system is stable.