Computer viruses are one of the most common problems computer repair services are called upon to fix. In 2010, Happy Hamster Computers removed more than 60,000 viruses from more than 3,000 computers. It can cost hundreds of dollars to fix an infected computer, and in some instances, computer repair is futile if the data gets destroyed and the hardware fried. The following is a look at some of the most expensive computer viruses to date.