ok couple of things
to mention thgat you have probably already tried
one absolutly free ad remover program removes ads spyware etc and havs never done a pop[up on me
go to
Ad-aware select the standard Version its free as a bird and truthfully i forgot it was on my machine for the Last 6 months since it doesnt remind me course as a free Version its totally manual not an auto runner not a continous shield or any of that
two check the left hand menu items for plugins and in plugins go to the vx2 page something there about a win nt/2k/xp thats EXtTREMLY diffucult to kill and they have a fix for it for free