What does Windows System Restore exactly back up and restore?

Restored:

• Registry (note: some current values will persist)
• Profiles (local only—roaming user profiles not impacted by restore)
• COM+ DB
• WFP.dll cache
• WMI DB
• IIS Metabase
• Files with extensions listed in the Monitored File Extensions list

Not Restored:

• DRM settings
• SAM hives (does not restore passwords)
• WPA settings (Windows authentication information is not restored)
• Contents of the My Documents folder(s)
• Specific directories/files listed in the Monitored File Extensions list
• Any file with an extension not listed in the Monitored File Extensions list
• Items listed in both Filesnottobackup and KeysnottoRestore (HKLM->System->ControlSet001->Control->BackupRestore->Filesnottobackup and keysnottorestore)
• User-created data stored in the user profile
• Contents of redirected folders