I have no idea if everyones keyboards are set up like mine is, but I have 2 USB ports on the back of mine for my mouse and whatever else (I used to plug my iPod into the other, but I kept getting some message which pretty much said I shouldn’t put it there). Anyway, my mouse keeps going out and not working, unless I fiddle around with the connection. It has progressively gotten worse, so I now have to hold it in one position with my hand while I use it in order for it to operate at all. Also, my keyboard will at times just go dead for no known reason, and I seem to have to re-configure it quite a bit (hit the keys next to the shift key), but this isn’t nearly as frequent as the mouse problem. Is this the keyboard, or the USB ports that are the problem? Or maybe a combination? Can you replace USB ports? I know it’s not the mouse because I plugged another one in and had the same result. Would it be better just to replace my keyboard?
You can replace the port but I’m not sure how. I’d take it to a store or a specialist and let them do it but it’d be more expensive. If both mouses behave the same way, plus the keyboard, my guess would be the port(s).
Thanks, Jack! 
I wonder what would be cheaper in the long run? To replace the ports or to get a new keyboard? I may have someone check it out just to see if it would be feasible.
You can buy a new keyboard and if it doesn’t help, return it. That’s what I’d do.
Replacing the keyboard will be your best bet, I think. The cost of labor is prohibitive. Peripherals like that aren’t intended to be repaired as much as they are just to be replaced.
As long as you’re going to replace it, take it apart yourself and see if you can tighten up a connection or something.
Some keyboard-mounted USB ports don’t have the power to run big things. I can plug a mp3 player into mine but it balks if I try to plug in something larger like my pen tablet. it may be best to use a computer-mounted USB for your mouse.