Formatting Compaq Hard Drives

Here’s the background. An employee had trouble with their Compaq computer, so they used the system restore CDs that came with it. Halfway through, they shut off their machine. When they tried to reboot – it couldn’t. I tried a boot disk to no avail-it couldn’t even recognize the format cmd. I decided to take the drive home and set it as the 2ndary master and format it via my OS. Here’s the deal, it’s a Compaq-they keep the BIOS/CMOS on the HD – How do I format it etc.? (where would I get the BIOS/CMOS – the web site doesn’t seem to have’em? – Where would I put’em? Is there a special way to Fdisk it OR install the OS as it is placed in unpartioned drive space?)