This morning I decided to read-up about running 32-bit software in 64-bit versions of Windows (XP, Vista, and 7).
This article in the Microsoft KnowledgeBase describes it quite clearly for Windows XP and Windows Server 2003. The same should apply to Vista and Windows 7.
- All 16-bit applications (such as program installers for 32-bit apps) will not work in 64-bit mode
- Most 32-bit software will run properly – perhaps with a performance hit or mild improvement
- 32-bit drivers will not work in 64-bit
- 64-bit Windows is designed to ignore 32-bit drivers should they somehow get installed
What are the advantages of 64-bit versions of Windows? Some performance improvement and the ability to access RAM up to 32 TB (instead of 4 GB). Keep in mind that 32-bit applications are still limited to 4 GB of addressable memory, even on a 64-bit system.