It's a scam that has been going on for years. Microsoft never makes unsolicited phone calls.
Is that call from Microsoft a scam?
http://answers.microsoft.com/en-us/protect/wiki/protect_other-protect_scanning/is-that-call-from-microsoft-a-scam/6718e389-8a00-4e4b-aca1-d07298ea4c19
Report the scam
http://support.microsoft.com/reportascam
Email and web scams: How to help protect yourself
http://www.microsoft.com/security/online-privacy/phishing-scams.aspx
Is it a genuine call from Microsoft?
http://www.computeractive.co.uk/ca/pc-help/2134917/genuine-microsoft
Avoid tech support phone scams
http://www.microsoft.com/en-gb/security/online-privacy/avoid-phone-scams.aspx
Do not fall for phony phone tech support
http://blogs.msdn.com/b/securitytipstalk/archive/2010/03/09/don-t-fall-for-phony-phone-tech-support.aspx
Aggressive, persistent Windows tech support scammers continue to stalk
consumers
http://www.computerworld.com/s/article/9248122/Aggressive_persistent_Windows_tech_support_scammers_continue_to_stalk_consumers
What is a Microsoft [Gold] Certified Partner?
http://securitygarden.blogspot.com/2011/09/microsoft-removes-gold-certified.html
And see this post by bhringer
http://answers.microsoft.com/en-us/protect/forum/mse-protect_scanning/recieved-eventvwr-cold-call/0f82d183-2046-469f-a2d2-8f9fa291f082#LastReply