Help me get rid of "security alerts" and "security centre popups"?

i think my computer has been taken over by a Trojan. pop ups come up, like the proper windows ones telling me i have "malware threats....your computer is infected with a black door Trojan blah blah blah" and internet explorer has been taken over by some weird homepage " security center" constantly tells me to buy (obviously hoax) anti virus etc software.obviously windows would never send me rubbish like this (at least i hope not!) so i need some help getting rid of it. i cant find a good adaware or w/e the other ones called that doesnt spam you with adverts or tell you to buy the official one. i think some other people have had this problem but i have not been able to find a solution for this. can anyone help me? get rid of it obviously

Help me get rid of "security alerts" and "security centre popups"?vista

Your computer has been infected with Smitfraud. Run the free RogueFix tool to remove it completely from your computer:

http://www.internetinspiration.co.uk/rog...

Carefully go through the instructions given in the page (note them serially before executing them one by one).

After your computer is clean and back to normal, download the free version of Super anti-spyware from

http://superantispyware.com/

Keep it updated and scan your computer whenever you face such problems in future.