The Back Board
Compared to the previous board, this one is a breeze. The only decision that you'll have to make is how much of your cabinet back so you want enclosed. We chose to leave enough open in the back to be able to slide Scott's PC out. This amount of opening also allows plenty of air circulation to keep the PC from overheating. We cut a board 20" wide x 31" long. Adjust the 31" measurement to your preferences.
We then clamped it into place (B), and drove four screws into it (C). The result is shown in picture D. See, it was simple!
Next up is the top of the cabinet.