Just wanted to say thanks to Ace Utilities - I have used it since 2003.
I recently had a corrupt registry during a Win8.1 update which caused my PC to reboot (hard crash) every 60 minutes!
I contacted Microsoft help, only to be told that it is probably a corrupt registry and they could offer one-time Advanced Troubleshooting session for $99... which I declined.
I searched my RegBak (Ace Utilites) folder and found I had done a Registry backup the day before the update. I restored from that, rebooted and the problem disapeared!
So thanks to Acelogix