On line or off, I get a pop up screen that says "you system may have critical errors" and they want me to go to some site and buy something... sometimes the message says "you may be infected with spyware", but it's the same ad. Same white and tan screen.

Hijackthis, Ad Aware, swsshredder, spysubtract ... nothing will get rid of this. I can be in the middle of writing something on Word or in the middle of a game, and this screen pops up and interrupts my work. Any ideas?

Love 'em or hate 'em, the Microsoft Anti-spyware tool got rid of a load of crud on my pc that the others missed. It's worth a try.

Welcome btw.

Hi Mitc

All this is, is ms messenger.
Here's how to get rid of it.
How to prevent Windows Messenger from running on a Windows XP-based computer