I've been working with computers for 15 years and I would seriously have to question why you were charged that sum of money. Like people have said previously it is easy to turn fact into fiction. Most viruses are simple to remove, nothing more than 10 minutes work. Sometimes there are viruses that aren't so simple to remove so formatting and reinstalling software is just far easier.... Backing up a 500GB HDD to a 3rd party machine and formatting the computer is only an hour process, I don't care what anyone says, it just doesn't take 3 hours. I've never charged for repairing laptops/desktops and even then it only takes the same amount of time. You've been shafted mate.