Unfortunately I just fell for this scam.  Don't let them into your computer.  I did now I have nothing but problems.

i just received a call from this number at my work place.  a man with an Asian accent named "james" informed me he was with Microsoft and my computer was emitting a dangerous virus and would shut down at any moment.  Working for AT&T we have  excellent IT support teams.  no way would I be getting a phone call from outside my company.  Our Anti virus software would have notified me way before I received a phone call from anyone.   I asked james for his call back number, he reluctantly provided it all the while in an urgent voice telling me I needed to hurry because my computer was going to shut down.  for the humor of it, I asked him what he wanted me to do...first he wanted me to turn on my computer.  well, that was funny as my computer is already on.  at this point I hung up on him.  I wished I had said.." hold on James,I work for AT&T, I am going to forward you to corporate security"