|Does it sometimes type Y or sometimes W?|
Seriously, if it's only typing vowels and it's doing that with more than one keyboard it sounds like malware.
Can you get into cmos/bios setup and see if some of the keys work there? Try booting to safe mode and see if you can get in. Or boot up with a cd or floppy disk and see if the keys work then.
Real men don't use AntiVirus; they just reformat