...period of time? Usually this happen periodically after few minutes. If I click at a place where I can type something, it will automatically type "A(H1N1)2009A(H1N1)2009A(H1N1)2009" exactly every few minutes(without quotes).

I use Microsoft Security Essentials to scan but found nothing. I tried to google but hard to find as I don't know the exact name of this virus/malware/watever.

Please help, I need suggestion on how to solve this. More info on this virus/watever is also appreciated.
Thanks