Their dorky company names and their cute little cars give off an air of friendly, helpful competence. But do the people who make computer house calls actually know what they're doing? As Erica Johnson's hidden-camera investigation reveals, most of the time the answer is "no". The Marketplace team modified a computer to simulate a common hardware failure. Then they called in the nerds. The result? Only three of the 10 technicians who saw the bait computer managed to correctly diagnose the problem — and to make matters worse, some of their faulty solutions came with very high price tags!