Hello,
I have an old computer with an Abit VH6-II main board that recently had a hard disk crash. It had Fedora Core 4 installed on it, and two disks. The primary disk is still intact, and the secondary disk was replaced. I added a 320 gig hard drive and upgraded the BIOS to support the larger disk. When I booted, both IDE disks where correctly identified, however, the boot got as far as the GRUB message being outputted on the bottom left hand of the screen. None of the keyboard buttons work except for Ctrl+Alt+Del sequence. I am wondering if this is a sign that the BIOS doesn't actually support the new drive ( since it is a large disk and the computer is old, dating back to 2000 ) or if Linux was installed on the drive that I recently replaced and that GRUB can't actually find the kernel image to load. How do I tell if its a hardware/BIOS problem vs. a software problem? Any help would be appreciated.

Boot a liveCD distro. If the old drive has any partitions, the liveCD should let you know. Mount the partitions (if any) and look at what's on the old disk.