REFORMAT PC XP - cannot get PC to boot to CD-rom to reformaT

Hello,

I am trying to reformat my PC with a version of XP that has been ripped (and I have been told works).

I have a GIgabyte motherboard MA77OT-UD3P and when I try to boot to CD-rom it won't - it will just restart my computer normally. I have tried changing the settings in Boot dick priority in BIOS settings, but this doesnt seem to work.
When I do this, the screen goes black, it starts loading devices/drivers etc, then says Boot CD/DVD ...
and then the CD runs in my computer (I can hear it spinning) and then it thinks about it...and then reboots normally as though it tried and could not.

Is this an issue with the CD rom?

Thanks!

p.s its not Corsair like my sub-category says - wouldnt give me Gigabyte option