Please give me advice for my windows XP (HP)

Hello,
I have an HP brand comp (not sure of the model) windows XP, it's about 7 years old. Anyway I noticed that the mouse was not working. I tried to reinsert it, and that didn't work. I also tried putting another mouse in but this also did not work. Then I tried starting it in safe mode. When I get to safe mode, the arrows won't work so that I can try resetting it to an earlier time. I cannot get it into safe mode at all. It just times out and then starts running and of course I can do nothing because the mouse won't work. I also tried hitting the little windows button to try to get to the start menu to open but this won't work as well. There is absolutely nothing that I can do! (At least that I know of). Does anyone know what this is or how to remedy it?