Mouse is slowing computer down?

I have a mouse I use for my computer, cause the mousepad is to small and wonky. Now my mouse won't work. I tried switching to another mouse, it didn't work. And if it's plugged into my computer when I turn it on, then the computer seems to stop. Sometimes my jump drives and other things will stop working randomly too. I think it is because of an update, but I don't know which one. what can I do? And, no, i don't know what system I have.