There is no need for a vote or for speculation. Microsoft are quite clear about their policy for contacting customers by phone - they state that they don't ever make unsolicited calls of that sort.
According to http://www.microsoft.com/en-gb/security/online-privacy/msname.aspx
Avoid scams that use the Microsoft name fraudulently
Common scams that use the Microsoft name
- Someone from "Microsoft Tech Support" calls to fix your computer
Avoid these dangerous hoaxes
If you receive an unsolicited email message or phone call that purports to
be from Microsoft and requests that you send personal
information or click links, delete the message or hang up the phone..
Microsoft does not make unsolicited phone calls to help you fix your
In this scam cybercriminals call you and claim to be from Microsoft Tech Support. They offer to help solve your computer
problems. Once the crooks have gained your trust, they attempt to
steal from you and damage your computer with malicious software
including viruses and spyware.
Treat all unsolicited phone calls with skepticism. Do not provide any
If you receive an unsolicited call from someone claiming to be from
Microsoft Tech Support, hang up. We do not make these kinds of calls.