After reading the other comments, I wonder whether the call was legit. I use the AVG Free virus protection software. Occasionally, it produces an error and I always click the box that says "yes, report it to the company."

Still, if they wanted to talk to me, they could have left a message (especially if they are giving out toll free call-back numbers). They hung up on my answering machine.
 Oct 08th, 2011
Claimed to be from a computer company investigating errors on my computer. Asked for me by name but didn't sound very convincing. Gave me a toll-free number to call them back at so I could verify they were for real - 1-877-778-9298
 Sep 30th, 2011
Asked for an individual by name person did not recognize the number; when asked to leave a message, caller refused.
 Sep 13th, 2011