How to boot from the DVD on a Dell Dimension 8400

The time has come to throw away my old Dell Dimension 8400, but before that I wanted to wipe the hard drive on it with DBAN so the one who scavenges the computer don’t get hold of whatever data I might have had on it. I burned the iso to a DVD-RW and put it in the old computer and entered bios and set it to boot from the  “Onboard or USB CD-ROM Drive” and completely removed the hard drive from the boot order list.

However when I restarted I just got an error message saying that there is no bootable device available and suggests that I should press F1 to retry or F2 to enter setup. Some googling suggested that many others have had the same problem and that it doesn’t matter if they try to boot from the DVD/RW drive or the CD/RW drive. So buying an empty CD and try to boot from the CD/RW didn’t sound like it would work.

With my setup the DVD/RW drive was the PATA slave and the CD/RW was the PATA master. After some more searching I found a simple solution that worked perfectly for me: Disable the CD/RW drive in bios so that the DVD/RW drive was the only optical unit discovered by the system. After I did this I could boot from the DVD just fine and continue to completely wipe the hard drive.