What types of files does System Restore change?
System Restore can make changes to Windows system files, registry settings, and programs installed on your computer. It also can make changes to scripts, batch files, and other types of executable files on your computer. Personal files, such as documents, e‑mail, photos, and music files, are not changed.
For example, if you download a personal file, such as a photo from a digital camera, on a Friday and then restore your computer to the state it was in two days earlier on Wednesday, the photo will still be on your computer.
However, if you install a photo viewing program on a Friday and then restore your computer to the state it was in two days earlier on Wednesday, System Restore will uninstall the program, and you won't be able to use that program to view photos.