Yet another sign of a struggling economy. PC repair shops are getting to be like auto repair shops and plumbers. They won't even look at your PC before they can charge you $30. The virus scan may be for their protection if they hook up your PC to their network. But that seems to be the first step in diagnosing problems. Virus scans may take 1/2 hour or more to install and complete. Thus the $30 charge. You may be able to save money if you tell them that you've done a complete virus scan yourself and show them a print out of the results.

Just curious what brand of scanner was giving you problems? You might want to disable your virus scanner software while you are scanning. May make a slight difference.