Windows reserves 1–5% of each drive for System Restore, which stores snapshots of the OS for rollback. Over time that reserved space fills with old restore points you will never use.
Short answer: open System Properties > System Protection, select the drive, click Configure, and either click Delete to remove every restore point or drag Max Usage down to cap future growth. Disk Cleanup's More Options tab has a one-click "delete all but most recent" button.
Deleting all restore points for a drive
Use this when you are confident the system is working correctly and do not need any old snapshots.
- press Windows + R, type
SystemPropertiesProtection, press Enter - under Protection Settings, select the drive (usually C:)
- click Configure…
- click Delete
- confirm — every restore point for that drive is removed
Next, cap how much space restore points may use in future:
- in the same Configure dialog, drag Max Usage down to 1–2%
- click Apply
Keeping the most recent restore point only
If you want a safety net but not a full history, Disk Cleanup's advanced option deletes all but the latest snapshot.
- press Start, type
cleanmgr, press Enter - choose drive C:, click OK
- click Clean up system files and re-select drive C:
- switch to the More Options tab
- under System Restore and Shadow Copies, click Clean up…
- confirm — Windows keeps only the most recent restore point
Turning System Restore off entirely
Not recommended on most systems — System Restore is cheap insurance against a bad driver or failed update. But on small SSDs where every gigabyte counts, you can disable it.
- SystemPropertiesProtection > Configure…
- choose Disable system protection
- Apply
If you disable it, pair with an external backup strategy (File History, a full image, or a cloud backup).
Better next routes
For other "System & reserved" savings, continue with Why Does "System & Reserved" Take So Much Space on Windows?.
For the broader Windows 11 cleanup picture, read How to Free Up Space on C Drive Windows 11 Natively.