If you have a problem with your system after running Registry First Aid you can restore the initial registry state. Registry First Aid makes three types of registry backups: system backup and full registry backup that are made before the registry scan and backup of modified registry entries that is made just before modifying the registry.
You can restore the registry by selecting either Restore Registry From a Full Backup or Restore From .reg Backup Files option from the Home screen.
If you found a problem with your system, first try to restore the most recent .reg backup file. Select the Restore From .reg Backup Files option at the first screen. You will see a list of available backups.
After selecting backup items to restore, click the Restore button. It is suggested to restart Windows® to be sure that registry changes were applied. After reboot check if a problem still exists. If a problem persists you can then restore all of the .reg backup files created after the date you are sure the system was OK.
If none of .reg backup files solved the problem then you can restore the registry from a most recent full backup. Such backups are created by Registry First Aid before scanning the registry.
Select the Restore registry from a full backup option at the Home screen. Follow the instructions.