toto pise priamo MS:
Manually Purge the Data Store
1. Click Start, point to Settings, and then click Control Panel.
2. Double-click System, and then click the Performance tab.
3. Click File System, and then click the Troubleshooting tab.
4. Click to select the Disable System Restore check box, click Apply, click to clear the Disable System Restore check box, click Apply, and then click OK.
5. Restart the computer when you are prompted to do so. When the computer restarts, the data store is purged and the System Restore feature begins monitoring the system again.