keyboard malfunction

I really dont know what the problem is. I just bought a new gaming keyboard today and suddenly when i clicked CAPS LOCK key QAZ and continuous Z comes out without me typing it. Any idea what the problem is? Thanks.

I bought a Dell Latitude E4300 a couple of years ago, refurbished, and I've had intermittent typing problems with it. The most common is that when I'm typing, for no reason whatsoever, the keyboard will act as if I've backspaced or tabbed and it will skip to a totally different part of the text...