I just got my computer back from my dad, who says he hasn't used it for a while. I got everything set up and when I pushed the power button it took me to the HP Invent screen, where it say press F1 for setup, Esc for boot menu, etc. My keyboard is either not working or the computer is frozen on that screen. I tried to search around the internet for solutions, but so far nothing I found has helped. I tried to restart it while holding the escape key, one solution I did find, and that did nothing. I even tried putting a CD in, to no avail. When I first start it I can hear the computer thinking, but then after about three seconds it stops. The computer is a hp a636n, and I've had if since 2004, if that's helpful.