you have been infected with a download trojan, probably from all that warez you download. don't pretend you don't know what i'm talking about
if you want to test my theory unplug or disable your internet connection and reboot. you will have no popups
my friend's computer had the same exact problem. even after a windows OS reinstall you may be reinfected from your other infected files. symantec norton anti-virus detected and repaired our problem easily. have you tried this software yet? there is a free trial download on the symantec site.