1st thing, stop using Internet Explorer. Too many bad things happen. Don't get me wrong, I use Avant Browser - same as IE, but when I need to do sensitive stuff, review galleries or what not then I use FireFox.
2nd - Download these free programs. Two are totally free but spy subtract is a 30 trial. It works the best.
Start your computer in "safe mode" and run these three programs. This should fix you up, also if you are using XP then restoring your computer to a date before you were infected will also help, but run these programs first. I'm not a wizzard at this stuff, but this is how I get rid of the problems you are having. And it works everytime. Also since you are still in safe mode, run a virus scan. Just to be completely sure.
Good luck!
Adaware SE -http://www.lavasoft.com/
Spybot -
http://www.spybot.info/
Spy Subtract -
http://www.intermute.com/