Error loading operating system?

When I reboot my computer, I get a black screen that reads "Error loading operating system". I wanted to just go ahead and format the HD, and reinstall the OS. I have made sure to set the CD ROM drive as the only available drive in the boot sequence. When I boot from the CD, I get a message that says "Strike the F1 key to continue, F2 to run the setup utility". I strike the F1 key, of course, to continue to boot from the disk, and I then get another message reading "strike F1 to retry boot, F2 for setup utility". I have opened up the computer, and checked all of the cables. Everything is fine. Also, I went into the BIOS, and ran a diagnostics. The hard drive IS being recognized, and it passed the diagnostics.