I Just Installed a Game. Will System Restore Delete It?by Aaron Parson
Windows' System Restore utility helps you turn back your computer's system to an earlier state, resolving errors that have appeared in the last few days by undoing all major changes since the machine last worked correctly. Though System Restore doesn't directly recover or delete your files, like photos or music, it will effectively uninstall any new programs and games since the restore date, while reinstalling programs you've recently deleted.
System Restore relies on restore points -- partial backups created before certain major events such as program installations, uninstallations and system updates. These restore points enable System Restore to reinstall removed programs even though you've deleted their data from your drive. Restore points also contain copies of the registry, a set of files that store all major system settings, including a list of installed programs.
Effect of Restoring
When you restore to an earlier point, System Restore replaces your current registry with an old version. Since the old registry doesn't contain data about new games and applications, your restored computer will no longer have those programs installed and could not run them correctly. System Restore therefore deletes them from the drive as well to avoid leaving behind non-functioning remnants.
If you need to run System Restore but don't want to lose your progress in a game installed since the restore point, you can manually copy the save data out of the game's files. Because System Restore doesn't delete user files, it won't erase your copied save file as long as you store it somewhere System Restore won't revert, such as your Documents folder or a USB drive. After your restore, reinstall the game, and then place your save file back in the game's folder. Save file locations vary by game, so check the game's manual or ask on the game's online forums if you can't find yours.
System Restore deletes only programs the system recognizes as installed. While this includes most commercial games installed either via disc or digital distribution, some smaller games don't actually install into Windows. If you download a game from the Internet, and opening the file immediately runs the game rather than an installer, Windows will see this file as user data instead of an installed program, and won't touch it during a restore operation.