OK i had to do this the other day on a coworker's laptop. he had malware on his comp that kept reappearing BECAUSE of a trojan worm.
go here:
www.bleepingcomputer.com
this is a forum for malware, spyware, and the like. this will get rid of any malware (spyware can be a cause of keyloggers)
there is a program called "Hijackthis" which is used to find all programs that can be malicious based on hooks. poke around the site, but there are tutorials and definitions for what the program spits out.
if all else fails, post ur Hijackthis! log on their forums, and someone will help you.