Windows 7 ships in both 32 and 64 bit when you buy one. If you install BOTH versions on the SAME pc (but on separate partitions, of course), will you be able to get both installations VALIDATED by Microsoft??? Anybody tried yet?
I don't think it would be a problem, but you're really only supposed to have one copy installed on the PC at a time. Retail disks give you the choice of whether you want to install 32 bit or 64 bit, but you only have one license. I would expect you to only be allowed to legally have one copy (either 32 or 64 bit) installed at a time, but not both.