you can run 32 and 64 bit programs but not 16 bit (which XP, Windows 98, etc. did). However (heres the catch) your drivers for your hardware have to be 64 bit drivers. Also have to have a 64 bit cpu.
When you install a 32 bit program it defaults to Program Files (x86) and when you install a 64 bit program it defalts to just Program Files.
Hope this helps
Can you run all the regular 32 bit programs in the 64 bit verson of vista?

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