What is the WinSxS Folder?
The WinSxS (Windows Side‑by‑Side) folder stores system components, including multiple versions of DLLs, drivers, and other files that Windows keeps for updates, rollbacks, and compatibility.
Why the Reported Size Can Be Misleading
File Explorer counts hard‑linked files multiple times, so the size shown (often 10‑15 GB) is larger than the actual disk space used. The real “Actual Size of Component Store” is usually 5‑10 GB on a healthy system.
Built‑in Tools for Cleaning
Never delete files from WinSxS manually. Use the tools that Windows provides; they know which files are safe to remove.
- Disk Cleanup – simple, GUI‑based, safe for routine maintenance.
- DISM (Deployment Image Servicing and Management) – command‑line utility for deeper cleaning and system repair.
- Scheduled Component Store Cleanup – runs automatically when the PC is idle.
Using Disk Cleanup
1. Open the Start menu, type “Disk Cleanup”, and run it as administrator.
2. Click “Clean up system files”.
3. Check “Windows Update Cleanup” (and other options you want).
4. Press OK and let the tool finish. It typically frees 2‑5 GB, more after a major OS upgrade.
Using DISM for Deeper Cleanup
Open PowerShell or Command Prompt as administrator and run:
DISM /Online /Cleanup‑Image /StartComponentCleanup– removes superseded component versions while preserving the ability to uninstall recent updates.
This command is more thorough than Disk Cleanup but still safe.
When to Use the /ResetBase Flag
Adding /ResetBase removes *all* superseded versions permanently:
DISM /Online /Cleanup‑Image /StartComponentCleanup /ResetBase
After this, you cannot roll back any previous updates. Use it only on a stable system where you are confident you won’t need to uninstall past updates.
Automated Maintenance via Scheduled Task
Windows includes a scheduled task that runs the component‑store cleanup during idle time. You can trigger it manually:
- Open Task Scheduler → Microsoft → Windows → Servicing → “StartComponentCleanup”.
Right‑click and choose “Run”.
If you shut down the PC frequently, the task may rarely run, so occasional manual cleanup is still useful.
Best Practices and Tips
- Run Disk Cleanup or the DISM command at least once a month.
- After a major Windows upgrade, run Disk Cleanup with “Previous Windows installations” to reclaim 10 GB +.
- Reserve the
/ResetBaseoption for systems that have been stable for several weeks. - Keep regular system backups; even safe cleanup can expose hidden issues.