Hit start button then go into control panel, go into administrative tools. Double click on services. Scroll down & find messenger, Right click & choose properties. Hit stop. then where it says startup type change to disabled. apply.
Thanks, that has stopped my problem too.
Though, won't the actual problem of the invasive 'ware still be there?
Mine started as soon as I first got connected to the net with a fresh reinstall... {yahoo.com specificly]
Unsolved 
