To store restore points, you need at least 300 megabytes (MB) of free space on each disk that is 500 MB or larger.
System Restore might use between three and five percent of the space on each disk. As the amount of space fills up with restore points, it deletes older restore points to make room for new ones. System Restore doesn't run on disks smaller than 1 gigabyte (GB). To learn more about how System Restore works, see What is System Restore?
You can manage the disk space that is used by System Restore by following these steps:
Open System by clicking the Start button , right-clicking Computer, and then clicking Properties.
In the left pane, click System protection.
If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
Under Protection Settings, click the disk, and then click Configure.
Under Disk Space Usage, move the slider to the right to increase the disk space that system protection can use or move the slider to the left to decrease the disk space.
If you decrease the disk space to be smaller than the space that is currently being used by system protection, older restore points, including previous versions of files, will be deleted.