As student I purchased the digital-river Windows 7 Pro 64-bit and I'm happy with it.
My university store also lets me buy a Windows 7 DVD for $ 43. I'm considering doing this for a possible second computer or to upgrade a laptop we have.
I want to buy the 64-bit version (since the future is 64-bit). It seems the university store either sells 64-bit or 32-bit DVDs, not one of the packages with both DVDs. Could I buy the 64-bit DVD and install one of the 32-bit bit versions with that 64-bit key (the digital river links had leaked) on the laptop for the time being?
the laptop only has 32 bit processor. But it might only live for 1-2 years. then I'd get some 64-bit computer.
I'd buy the Pro-version. I don't think there is anything illegal, since I legally buy two different student discounts from different vendors. I also will use that one key only for one license at a time (and also assume once I register online MS makes sure it only works on one PC).