Interesting. We've had three phone calls from different people local to here, saying that someone phones up saying he's from Microsoft and there's something wrong with their PC. Seems like a persistent guy. The website www.mypccare.info (be careful visiting these kinds of sites: don't do it in IE!) seems at first glance to look legit, but a closer look shows it's pretty shoddy.
Anyway, whois tells me that the domain was registered by Abhishek Jaiswal in Calcutta. Not as UK as that flag on the website suggests then. Googling for the text on the page, shows the exact same quote on a list of similar "support" sites.
The scam is that they try to get you to allow remote access to your computer. People have lost lots of money through these types getting access to their financial information. Be careful out there!