System Restore regularly tracks changes to your computer's system files, and uses a feature called System Protection to create restore points. System Protection is turned on by default on all hard disks on your computer. You can select which disks have System Protection turned on.
Turning off System Protection for a disk deletes all restore points for that disk. You cannot restore the disk until you turn on System Protection again and a restore point is created.
Open System by clicking the Start button , clicking Control Panel, clicking System and Maintenance, and then clicking System.
In the left pane, click System Protection.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
To turn on System Protection for a hard disk, select the check box next to the disk, and then click OK.– or –To turn off System Protection for a hard disk, clear the check box next to the disk, and then click OK.
System Restore doesn't protect FAT32 and other FAT disks because FAT disks don't support the use of shadow copies. Shadow copies contain information about changes to documents and system files. Shadow copies require the NTFS file system. In this version of Windows, System Restore uses shadow copies to create restore points. If you store system files on a FAT disk, you cannot use System Restore to undo changes.