Keyboard errors, mouse disconnects, on-screen keyboard errors

I was wondering if any of you had any idea what is going on with my computer. In bios it has a whole list of keyboard errors that happen all the time. When I am typing an "s" will type "sasasasasasasasasasa" forever, a "w" will be "wqwqwqwqwqwqwqwq" and an "x" will type "xzxzxzxzxzxzxzxz" infinitely. Even If i don't type anything it will repeat "sasasasasasasasasasasasa". I've tried 3 keyboards with the same problem happening, and my mouse randomly quits working and I have to unplug and replug it for it to work. I have formatted my computer twice and still get the same problem, so it's not a virus. It does it even in setup. Also, even more annoying is the windows On-Screen keyboard I have to use to type, as it has the SAME problem and even opens random windows and programs with certain letters. At first I thought it was my USB controller going out, but if it was, then how come the windows On-Screen Keyboard still does this?

Any help would be amazing, this is so damn annoying. Have any of you heard of this? Should I just get a new motherboard since it might be a bad controller of some sort?

It's called a bad chip set. Replace motherboard.

I've tried all the USB ports and they randomly do the same thing, also, no PS ports on my motherboard, although I agree they were way better, never had a problem with them.

I'm thinking its a chip set problem with a USB controller. but that doesn't explain it also happening in the on screen accessibility keyboard. So weird. It is a crappy dell motherboard so that kind explains it.

Any other recommendations? Could a power supply going bad also have an effect causing things to go haywire? Everything else is is perfect though. Games run flawless except I can only play games with just the mouse, heh.