I think you might be able to turn it off in bios, but i could be wrong.
I was actaully refering to when you boot from teh cd and around the time when it says to press f3(i think) to install scsi drivers keep hitting f5(maybe f8) and you will have the option to choose whcih type of pc you have examples :standard uniprocessor, multiprocessor, acpi. Choosing standard uniprocessor pc(or something to that effect) should give you some extra irqs.
Yea I use ntfs these days, guess cause I never have to use dos anymore (cant access ntfs in dos).