Hi frostybear,
If you have already downloaded the 64bit edition, then the easy way to find out if it will work is to try to boot from the DVD. If it boots into a live system, then it will. If you get a message stating that it's the wrong architecture, then it wont.
To play it safe, go with the 32bit edition instead. Does the following link help?
http://www.ultimateeditionoz.com/downloads/Welcome to the forums.
P.S. I believe there are three versions of Ultimate Edition 2.4 available (someone please correct me if I'm wrong);
2.4 32 bit
2.4 64 bit
2.4 Gamers 64bit.
Cheers.