You should buy elsewhere and show a copy of the reciept to the loud mouth that told you that garbage! One other thing to know about viruses is that there are various types. Some may only infect a few files and later spread when those are opened even after copied to another drive.
Others are self replicating typically the I-Worm type that spreads from one system online to another if you are connected online. Chain letter emails from unknown senders with a file attached indicates someone else's system was infected and the bug is using the online connection there.