How do I get rid of a pop-up virus on my pc?

I have Norton 360, but it doesn't stop the pop-ups from randomly opening when use the internet. Mostly they say CiD: then some add or something... I have allready tried scanning with Norton 360, Adaware Personal, Spybot, and Spyware Blaster, but none of these stop the random pop-ups. It is making my internet sluggishly slow. PEASE HELP!! thanks