Yep, you dont want to find out the hard way...its just a total scam, there are a few of them getting around at the moment.
Bit like that Nigeria scam thing really isnt it.....makes you wonder how many people they have caught out.
Helps when you have a Computer techie in the family too lol. the first time it happened to me, I had a wonderful frinds fix mine for me, and I took notes so if it happened again, I could fix it with out having to bother her! Glad I did