System Restore helps you restore your computer's system files to an point back in time. It helps you undo system changes to your computer without affecting your personal data. It is worthy to note that System restore affects Windows system files, programs, registry values, scripts, batch files, and other types of executables. System Restore in Windows 7 and Vista works a bit differently than it does in Windows XP in that it uses the Shadow Copy feature in which it creates a snapshot of your drive at a certain point of time.
Then click on System Protection to display the System Restore configuration menu.
You can select a drive or partition and click on the Configure button to get detailed configuration information about it. This includes the percentage that is currently allocated for System Restore in MBs along with the current usage.
By default System Restore can save system settings and previous versions of files. You can however choose to restore only the previous versions of files as shown in the figure above.
You can also selectively turn System Restore off for a specific drive or partition. This was also possible in Windows XP