I had the same phone call today also...wanted me to turn the computer on and " fix" it for me as they said they kept receiving reports of errors from my PC..but I was not having any issues on my computer. Hahaha...hackers?
Man with a thick accent told me I could get 6% interest on my visa for life. Then he asked me for my security code on the back. I asked what visa and he mentioned two banks I'm not associated with.
be careful not to give any information to any of these people claiming to be from windows or visa. If you have been a victim of this, be warned that a lot of credit card companies will not help you get your lost money back.