|System Restore will not restore user accounts or the data in user profiles. There are utilities that may be able to restore deleted data. Others can assist with that. But until then it is vital that as little as possible be written to the drive or this data will be overwritten. Overwritten data cannot be restored.|
You really need to have a backup of important data. Hard drives fail and data can be lost for a variety of other reasons, such as deletion of user accounts. Not having a backup is asking for trouble.