hello everyone my name is john jefferson i know how to repair computers except one computer in my home will not let me repair it and thats the dell dimension 4300.first its cd drive brake on me right after i fixed four pc's already.so im working on that dell dimension 4300 and one thing it did was lose cd-rom on the boot menu and the boot sequence.so this is what i tried i untached its hard drive and i had old hard drives they didn't work but they could get my cd-rom back.so one of the hard drives got my cd-rom(not installed) threw.so i go back to put it to its hard drive and they were unnoticed.no hard drive is on the boot menu and on boot sequence it says hard drive not installed/ so i write this cause this is a problem anybody know answers for this please contact-----jbernj7@yahoo.com/ or give reply to add