They are at work, So I won't do anything until Tuesday or Wednesday.
They are sitting side by side on a desk with a firewire cable connecting them. I booted the "Good" MAC from the 10.6.3 DVD with no problems, and did a fresh install of OSX. So something is causing that other Mac to not work.
I don't have the original CDs that came with either of the computers.
I have an OSX 10.6.3 CD that I bought at Best Buy a few years ago.
When I hold option and boot the computer, It doesn't show any kind of boot menu with different options.
I have access to everything now. External hard drives, another identical MAC (with a fresh install).
Maybe that hard drive is not connected correctly.