computer stops at initial start up after boot from cd prompt

I have 2 different hard drives that I have had tested and have been told they are okay. So when I hook them up in my system (that I have also been told it is okay), it stops at the boot from cd prompt, right above it the line says, unknown flash, then the boot from cd line and then it stops. I have unplugged the cd rom and the floppy drive to see if that is the problem but the computer is still stuck there. What do I try next? I even put the windows xp disk in to try and see if I could do anything with it, it shows the checking your hardware configuration line then that disappears and nothing else happens. So not sure if it is something with the hardware, hard drive or what is happening. Thanks again for any advice.

Wes

What kind of hard drives? IDE or Sata? if they are IDE are the jumpers set correctly? do BOTH hard drives have OS's on them?

They are IDE drives and both have windows xp on them. The jumpers haven't been switched since taken out to be tested. What other things can I look for?
Thanks!