If you have another keyboard, I would try it and see if you got the same results. If you do not, then the keyboard is malfunctioning. If you get the same error, something is probably wrong in your bios. Those would be the steps I would take. Also, did you install or remove any software right before the problem began. If you can remember, you could try restoring your computer to that point, if the restore point is available.
I have seen keyboards do weird things over the years. Once I manage to fix one by turning it upside down and shaking it. You would have been amazed at what fell out of that thing. Worked fine after that.