2 questions. Please answer seperately.
I want to dual boot Windows 7 Ultimate with Windows 7 Professional. Is it possible?
Can Windows 7 32-bit be dual boot with Windows 7 64-bit?
Its fairly easy, install either version of W7, once installed use device manager to shrink the partition to make room for the second W7 install, once this is done boot from the second W7 DVD and install it on the second partition you just created, once done you will have a boot loader show up before windows loads to choose which W7 you want to boot into.
you should research how to install windows 7 to a "native boot" vhd. here's a link to get ya started:
You can install any edition or 32/64bit combination you want.
The steps outlined in that blog are: 1) start windows 7 installation from dvd 2) run diskpart to create the vhd where you will install and boot windows 3) install windows to vhd
Check out EasyBCD to let you manage the dual boot OS options when your computer starts up. much easier than using the command line tools.