Adaware is free, but not all adware programs will detect all keyloggers.
Try this link it lists some programs.
Did you know that keyloggers can be downloaded onto you computer via ecards, and other email without you knowing?
I learned a lot over the last little while, my compter was being remotely accessed for how long, and had no idea.
It's good to try a couple of different programs, not ever program will catch ever spyware.
Another good free program that I totally suggest is http://www.winpatrol.com
Scotty the internet watch dog is a great program to leave running in the backgroud.