What files are changed during a system restore?
System Restore affects Windows system files, programs, and registry settings. It can also make changes to scripts, batch files, and other types of executable files created under any user account on your computer. System Restore does not affect personal files, such as e-mail, documents, or photos, so it cannot help you restore a deleted file. If you have backups of your files, you can restore the files from a backup.
For more information you can visit the following website to know more about sysetem restore
http://windows.microsoft.com/en-in/windows7/system-restore-frequently-asked-questions