Hi VulcanClaw,
I guess the PM reply did not help.
You can follow the procedure in this tutorial. If you do not have a upgrade version of your 32 bit Vista, then just enter the product key during the first install and skip the second install part and go to step 23.
How to Do a Clean Install of Vista From a Upgrade Version
The main thing is that you will need to boot from your 64 bit Vista Installation DVD. Check the BIOS to make sure that the CD/DVD is listed first in the boot order. You can enter the BIOS settingd by pressing usually
F2 or
DEL while the computer is booting up.
Shawn