are you sure the jumper is right?
if it's the only thing on the ribbon cable, it should be set to master
just to be clear - the cdrom used to work at one time and was letter "D"?
is there an option in the setup program within the BIOS to boot from cdrom?
if so, set it to boot to that first, then put in your Windows disk and restart....if it does, exit out of the Windows program , remove the cd, and restart