# Is It Safe to Delete the WinSxS Folder? How to Shrink It

> Why WinSxS looks huge, how to measure its real size with DISM, and the three supported ways to shrink it on Windows 10 and 11, with what each one costs you.

Canonical: https://bytesweep.app/answers/is-it-safe-to-delete-winsxs.html
Last updated: 2026-11-04

## Is it safe to delete the WinSxS folder?

Why WinSxS looks huge, how to measure its real size with DISM, and the three supported ways to shrink it on Windows 10 and 11, with what each one costs you.

- By [Shajeen Ahamed](https://bytesweep.app/about.html#author)
- Updated 4 November 2026
- Steps checked against Microsoft's documentation

**Short answer**

No. Microsoft warns that deleting files from `C:\Windows\WinSxS`, or the folder itself, can leave Windows unable to start or update. It also looks bigger than it is: most of its files are hard links shared with the rest of Windows. Shrink it the supported way, with `Dism.exe /Online /Cleanup-Image /StartComponentCleanup` or Disk Cleanup's Windows Update Cleanup.

### What is the WinSxS folder?

WinSxS is the **component store**: the master copy of the files that make up Windows, kept so that Windows can install updates, turn optional features on and off, roll an update back and repair damaged system files. When an update replaces a component, the old version stays for a while in case you need to go back, and Windows removes superseded versions on its own schedule.

Microsoft's warning, from [Clean up the WinSxS folder](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/clean-up-the-winsxs-folder): "Deleting files from the WinSxS folder or deleting the entire WinSxS folder may severely damage your system so that your PC might not boot and make it impossible to update." Taking ownership of the folder to force a delete, which some guides suggest, is exactly that.

### Why does WinSxS look so big in File Explorer?

Hard links. Most files in WinSxS are the same files you find in `C:\Windows\System32` and elsewhere: one copy on the disk, reachable from two places. File Explorer counts the file once in each place, so the folder looks far larger than the space it actually costs. Microsoft: "there's usually only one copy of the file and the rest of the copies are actually hard links."

### How do I find out how big it really is?

Open a Command Prompt as administrator and ask DISM:

```
Dism.exe /Online /Cleanup-Image /AnalyzeComponentStore
```

It takes a minute or two and prints these lines. The two that tell you what cleanup can win are **Backups and Disabled Features**and**Cache and Temporary Data**; together they are the store's real overhead.

| Line in the output | What it means |
| --- | --- |
| Windows Explorer Reported Size of Component Store | The size Explorer would show, with hard links counted twice |
| Actual Size of Component Store | The size with hard links counted once |
| Shared with Windows | Files that are also part of the running system. Not overhead: removing them would remove Windows |
| Backups and Disabled Features | Older component versions kept for rollback, and features that are switched off. Overhead |
| Cache and Temporary Data | Files used to make servicing faster. Overhead |
| Number of Reclaimable Packages | Superseded packages that cleanup can remove |
| Component Store Cleanup Recommended | Yes or No: whether a cleanup is likely to help |

Microsoft's own example reports 4.98 GB in Explorer, of which 4.38 GB is shared with Windows, leaving about 507 MB of overhead. If the last line says No, cleanup will not free much and the space problem is elsewhere: see [why the C drive is full](https://bytesweep.app/answers/why-is-my-c-drive-full.html).

### What are the supported ways to shrink it?

| Method | What it does | What it costs |
| --- | --- | --- |
| Do nothing | The StartComponentCleanup task runs when the PC is idle and removes old component versions 30 days after their replacement was installed | Nothing. It has a one-hour limit, so it may not finish in one run |
| Run the task now | `schtasks.exe /Run /TN "\Microsoft\Windows\Servicing\StartComponentCleanup"` | The same as above, now |
| Disk Cleanup, Windows Update Cleanup | Clean up system files, then tick Windows Update Cleanup. On Windows 11, Settings, System, Storage, Cleanup recommendations offers the same | Nothing you would miss |
| DISM StartComponentCleanup | `Dism.exe /Online /Cleanup-Image /StartComponentCleanup`: removes superseded versions immediately, with no 30-day wait and no time limit | You lose the 30-day window to roll back a recent update's components |
| DISM with /ResetBase | `Dism.exe /Online /Cleanup-Image /StartComponentCleanup /ResetBase`: removes every superseded version of every component | Updates installed so far can no longer be uninstalled. Future updates still can |

Run the DISM commands from an elevated Command Prompt and leave the window alone until it reports that the operation completed; it can sit at one percentage for minutes. Microsoft also "strongly recommends not disabling component cleanup", so leave the scheduled task switched on.

### Is /ResetBase worth it?

Only when you need every last gigabyte and the PC is stable. It frees the most, but if a recent update turns out to break something, the usual fix (uninstall that update) is no longer available, and the way back becomes a repair install of Windows. On a work PC managed by an IT department, leave it to them. For a home PC, the plain StartComponentCleanup command is the better trade.

### Do any cleaners do this safely?

A cleaner that deletes files inside WinSxS is doing the dangerous thing Microsoft warns against, however it is labelled. A safe one calls the same DISM cleanup you can run yourself. Bytesweep for Windows does that: its Maintenance page runs component store cleanup through DISM, never by deleting files. Like every DISM operation it cannot be undone, and the app says so before you confirm; the rest of what it cleans can be put back for 7 days. Bytesweep for Windows comes from the Microsoft Store, is free to try for 3 days, and cleaning needs a $29.99 licence, once per computer.

### Sources

Read on 4 November 2026. If something here has changed, write to [support@bytesweep.app](mailto:support@bytesweep.app) and it will be corrected.

- [Microsoft Learn, Clean up the WinSxS folder](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/clean-up-the-winsxs-folder)
- [Microsoft Learn, Determine the actual size of the WinSxS folder](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/determine-the-actual-size-of-the-winsxs-folder)

### Keep reading

- [**Why is my C drive full, and what can I delete?**](https://bytesweep.app/answers/why-is-my-c-drive-full.html)
- [**Can I delete hiberfil.sys and pagefile.sys?**](https://bytesweep.app/answers/hiberfil-sys-pagefile-sys.html)
- [**Bytesweep for Windows**](https://bytesweep.app/windows.html)
- [**All answers**](https://bytesweep.app/answers/)

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