[citation][nom]Hatecrime69[/nom]the retail product keys (like the student discount version) work with both the 32 or 64 bit version (the oem versions however, do not)[/citation]
@Hatecrime69 - I do not believe that this is correct. Just yesterday, I installed 32-bit Windows 7 Professional using a retail 32-bit DVD and an OEM key that came with 64-bit media. Activation was successful.
All retail, partner and licensing keys (MSDN, Technet, Assurance, MAPS, etc.) are for definitely interchangeable.