New
#71
1. OK, so we ruled out the mouse (finally)!
2. Anytime I buy electronics, I give it 50/50 chance of working out of the box. But I am not saying your keyboard is broken. Using a different keyboard may tell us if there is something specific about that particular model and how it is configured with your hardware/software. It is just the easiest thing to do, change to a different keyboard and see what happens.
3. Do you have a friend you can try your keyboard in their computer?
Yes, something may be "wrong" with your pc, but to troubleshoot, you have to try different things to rule them out. Or take the keyboard to another computer to help determine.