Microsoft changed my screen background

As soon as I clicked on a Microsoft message offering Antivirus XP 2008, and before I downloaded it, my screen background was changed to their own all blue. I had to reload my own screen image, the name of which even disappeared from the panel control.
Why did they change it and what right do they have to change it ?

Also:
I thought I was well protected with Ad Aware, Spybot and AVG. But when I downloaded and ran Antivirus XP, it found 1842 (!) viruses in my computer.
How is this possible ? And how can a computer run normally with 1842 viruses in it ?

I hate to say this but you have been had.
Antivirus XP is NOT a Microsoft product.
Just the opposite, it is a Trojan.
Instructions in the link for removal of Antivirus XP. ( Microsoft site).

I had the same problem a month ago. Here is the thread and the advice I got. It worked like a charm.

Thank you Myglaren.

I’ve removed it immediately. :o :o and :mad:

Now go and get AntiSpywareMaster so this will never happen again! :wink: