WinSxS says 11.8 GB and the real answer is 6.2 GB
The component store is built from hard links, so every folder size you have been shown is wrong. What it really holds, measured, and the one command that cleans it.
Sort C:\Windows by size and WinSxS is usually the largest folder on the drive. Every cleanup article tells you not to touch it, which is correct, and almost none of them tell you the size you are looking at is not real.
Why three tools give three answers
The component store is built almost entirely from hard links. A hard link is a second name for a file that already exists somewhere else: the bytes are stored once and two folders both point at them. WinSxS is how Windows keeps every version of every component it might need to repair or roll back, and it does that by pointing at files that are already in System32 rather than copying them.
A tool that walks the folder and adds up file sizes counts those bytes once per name. That is how 6.2 GB becomes 11.8 GB. Explorer is closer because it knows about the links, and DISM is right because it asks the servicing stack what is actually stored.
Ask the tool that knows
DISM /Online /Cleanup-Image /AnalyzeComponentStoreRun it in a Command Prompt or PowerShell opened as administrator. It prints the three numbers that matter: the actual size, how much is shared with Windows, and how much is backups. It also tells you whether cleanup is recommended, which on the measured machine it was, with two reclaimable packages.
What is safe to remove, and what is not
| Part of the store | What it is | Can it go |
|---|---|---|
| Shared with Windows | Files also in use elsewhere | No, and removing them breaks Windows |
| Backups and disabled features | Superseded components, rollback data | Yes, with DISM |
| Cache and temporary data | Servicing leftovers | Yes, with DISM |
DISM /Online /Cleanup-Image /StartComponentCleanupThat removes superseded components safely. Adding /ResetBase also removes the ability to uninstall any update installed so far, which is a real trade: it reclaims more and it means a bad update cannot be rolled back.
What never to do
Do not delete anything inside WinSxS by hand, and do not let a cleaner do it either. The folder is not a cache: it is the servicing store Windows repairs itself from, and removing files from it produces a machine that cannot install updates and cannot be repaired without a reinstall. The hard links are also why deleting a file there frees far less than its listed size suggests.
If it is genuinely large
On a machine that has been upgraded through several Windows versions the backups portion grows, and that is what StartComponentCleanup is for. Windows also runs it automatically on a schedule, so a store that reports cleanup as recommended is usually a machine that has been on for a long stretch without an idle window.
The other folder in C:\Windows worth knowing about is the installer cache, which measured 5.7 GB on the same machine and is genuinely misunderstood in a different way.
Common questions
Can I delete the WinSxS folder?
No. It is the servicing store Windows repairs and updates itself from, not a cache. Removing files by hand produces a machine that cannot install updates or repair itself. Use DISM, which removes only what is genuinely superseded.
Why does WinSxS look so big?
Because it is built from hard links: the same bytes appear under several names, and any tool that walks the folder counts them once per name. On a machine measured in September 2026 a walk reported 11.8 GB where the actual store was 6.2 GB.
How do I safely clean WinSxS?
Run DISM /Online /Cleanup-Image /AnalyzeComponentStore to see what is reclaimable, then DISM /Online /Cleanup-Image /StartComponentCleanup. Both need an administrator prompt.
What does ResetBase do?
It removes superseded components and also the ability to uninstall any update installed up to that point. It reclaims more space and it means a faulty update cannot be rolled back, which is the trade to make deliberately.