|sounds like a keylogger is installed.|
Run these progs and see how that works:
1- trojan Remover
2- Hitman Pro
Run them till they are clean
The only sure way to get rid of a keylogger is to reformat the HD, BUT that is a last resort. We can try to remove it first.
If the above don't help ther are more cleaners.
Some HELP in posting on Computing.net plus free progs and instructions Cheers