|Sounds to me like the keyboard (either USB or PS/2) port may have gone bad, though unlikely, it is possible.|
More likely, you've been infected with some sort of data-eating virus that likes to mess with your keyboard. Try to backup your data if you haven't already, or if you can at all... DO NOT connect to the internet until you're all backed up unless absolutely necessary - and by do not connect, I actually mean UNPLUG the ethernet cable so there is no way you can be infected with more viruses. Try to boot to external HDD, and copy old data over if you can.
hope this helps, sorry if it's unclear I don't have much time and i'm still getting used to this new keyboard LOL.