need help removing a virus and 56 trojans

[jamirez]

have problems with virus (5) effecting the tool bar especially appearance where the application might be duplicated and freezes the pc and causes problems with programs

trojan downloader.twetti and trojan downloader.js.kazmet have infected my pc. please help me remove these as i don't have a clue how to do it?
thanks jamirez

[Aleksandra]

Please, read the rules and make 3 logfiles (syscure, syscheck, hijackthis).