Cannot boot XP from second disc drive in Dimension 4600

Hello, I am trying to do a clean install of XP on a Dimension 4600. When I rearrange the boot order to boot from the disc it just goes straight to Windows. If I use the F12 menu to boot from the disc, it goes straight to Windows. I can boot the disc from My Computer, (so I know that the second cd/dvd drive works) but it doesn't let me format the partition this way and I want to delete the whole partition and start fresh with a real clean install.

The PC has two disc drives, the one on the top doesn't work (even though device mgr says it is working properly) (would not open, got it open and will not close now) and I also get a disc drive 0 seek failure message on startup. I tried to boot from a flash drive but gave up on this - I just couldn't get it to work and was already frustrated by that before this cd fiasco... I'm assuming that the XP cd will not boot because it is looking in the first optical drive to boot...

1. Can I just disable the first drive so it will recognize the second to boot from it?

2. If not, can I reassign the drives so that the computer uses the second one first?

3. If neither, can I just unplug it and/or remove it and a.) leave it or b.) put the second drive in its place?

Thank you in advance for you time and help!