Computer Whiz (Fallout 3)

Computer Whiz is a Fallout 3 Perk.

Fail a hack attempt and get locked out of a computer? Not if you’re a Computer Whiz! With this perk, you can attempt to re-hack any computer you were previously locked out of.

Commentary
Many players find this to be a useless perk. As you could, of course, quick save before hacking and quick load if you fail. But an even simpler solution is to power the terminal off before using up your last attempt, and then try again.

Just make sure you don't use your last attempt and refill your attempts with the ,[].{}, and <> entries. These entries also remove duds, but there is almost always an entry that refills your attempts.