This is a scam.  These people claim to be from Microsoft Support and will tell you that there is a virus on your computer, when there is nothing wrong with your computer.  DO NOT TRUST THESE PEOPLE.  They will ask to input your credit card details in a "secure website"

i just got call my self i do belive its a scam his name was sharrn willsonand the tecs name was sam watson

NO!!
All of them do not pose as microsoft....The one mentioned by Tim and Newman is a genuine company and i am very satisfied with their regular support.
Thumps Up!
Windowssupportservice.com
Good work

IGNORE THESE PEOPLE - THEY ARE SCAMMERS!!!I got a similar call yesterday (in Sydney) from an Indian woman claiming to be from "Windows Support Centre". I had no intention of doing what she *told* me to do but I played along and asked her how I could check her credentials and she gave me this (02) 8006 0103 number. Then I did some checking and found this article in the Guardian UK, dated 18 July 2010 (!):http://www.guardian.co.uk/world/2010/jul/18/phone-scam-india-call-centres

Hi All,   I have a very good news for you all the person called Shaun Wilson is a big scammer who always tries to take money out from people by telling them that they are from Microsoft.I have investigated this matter & i have got some results related about him .This scam is running by a company which we cant say a company is actually a small room in which only two scammers call people by the same name Shaun Wilson.Their real names are Maajid Jehangir & Mudasir Sofi probably an indian or pakistani names but i have done a research with the help of western union as they have taken money from me through western union.They are from india somewhere in J&K-Soura as police have got all their details from western union & i am sure that they will be in jail soon as i have taken this issue with the ministry of justice UK.  I was aware that i am sending money to scammers & before i send money to them i informed Police,Western union & MOJ so that they will keep track of all the their records.Even i have got the scanned copy of their id proofs which i have verified is real not fake.This investigation has been completed today & soon i will inform you all about their imprisonment.

IGNORE THESE PEOPLE - THEY ARE SCAMMERS!!!

I got a similar call yesterday (in Sydney) from an Indian woman claiming to be from "Windows Support Centre". I had no intention of doing what she *told* me to do but I played along and asked her how I could check her credentials and she gave me this (02) 8006 0103 number. Then I did some checking and found this article in the Guardian UK, dated 18 July 2010 (!):

http://www.guardian.co.uk/world/2010/jul/18/phone-scam-india-call-centres