Need to load software on external CD/DVD drive

Hello to all!!!!
I've tried to qlean as much understanding from the many helpful postings on your forums, but still I hope that you can help me with this quandry!
Reconfiguring a Compaq 5304 for teenagers to listen to music and skateboard videos (and do homework????). OS is Windows 98. I'm adding more RAM to max capacity, and an external hard drive.
For now my concern is how to load an upgrade of Windows XP when the original CD drive is faulty. I will be trying to use a removable Disk in Drive F that is an external CD/DVD burner.
Is it best that I first disconnect the old internal CD drive? or can I get the computer to use the F drive first (like a default printer?)
Computer properties shows the F drive as the new CD drive, but I don't know how to get it recognized first???
Do I need to put new commands in "Start-up" or BIOS (which I've never tried)?
Thanks for all the helpful information from everyone's challenges and experiences.:heartlove
qlearner