doing a bit more research, this is what microsoft says System Restore restores or doesn't restore. (interesting, I didn't know it until now...
)
Restored:
•Registry
•Profiles (local only; roaming user profiles are not affected by restore)
•COM+ DB
•WFP.dll cache
•WMI DB
•IIS Metabase
•File types monitored by System Restore as specified in the SDK document Monitored File Extensions
Not restored:
•DRM settings
•Passwords in the SAM hive
•WPA settings (Windows authentication information is not restored)
•Specific directories/files listed in the Monitored File Extensions list in the System Restore section of the Platform SDK e.g. 'My Documents' folder
•Any file types not monitored by System Restore (.doc, .jpg, etc.)
•Items listed in both Filesnottobackup and KeysnottoRestore (hklm->system->controlset001->control->backuprestore->filesnottobackup and keysnottorestore) in the registry
•User-created data stored in the user profile
•Contents of redirected folders