Possible Duplicate:
When reinstalling Windows 7, does the language, version, architecture (64-bit or 32-bit) or source (OEM, retail, or MSDN) matter?
My uncle bought Windows 7. It comes with 32-bit and 64-bit install discs. He has a printer that has a 16-bit installer and so has to install the 32-bit version of Windows.
What I want to know is if, later down the line, he wants to go 64-bit can he just wipe his machine and install using the 64-bit disc or does he have to buy another copy of Windows?
