try this. go into add remove programs and switch to windows components, REMOVE Internet Exploder (*ahem* i mean internet explorer) entirely and install Firefox
you can find the install for firefox [here]
firefox does not sup[port the pesky popup hijacker and since IE isn't around the hijacker is useless and you can take your time exterminating it.
you sould also look into what exactly you did just before this problem started, did you download/install any programs from unknown sources? did you visit any 'shady' websites? did a popup window open and you clicked 'ok' without reading what exactly it said? do you have up to date virus protection? do you have the real time virus protection option turned on? have you done a full virus scann of all storage media/drives recently?
Student: "Umm sensei, the question on the board is wrong."
Teacher "SHAAAADD UP!"