What is the difference between 32-bit and 64-bit versions of Windows?
The terms 32-bit and 64-bit refer to the way a computer's processor (also called a CPU), handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system. For more details, go to A description of the differences between 32-bit versions of Windows Vista and 64-bit versions of Windows Vista online.
Can I run 32-bit programs on a 64-bit computer?
Most programs designed for the 32-bit version of Windows will work on the 64-bit version of Windows. Notable exceptions are many antivirus programs.
Device drivers designed for 32-bit versions of Windows won't work on computers running a 64-bit version of Windows. If you're trying to install a printer or other device that only has 32-bit drivers available, it won't work correctly on a 64-bit version of Windows. If you are unsure whether there is a 64-bit driver available for your device, go online to the Windows Vista Compatibility Center.
Can I run 64-bit programs on a 32-bit computer?
If the program is specifically designed for the 64-bit version of Windows, it won't work on the 32-bit version of Windows. (However, most programs designed for the 32-bit version of Windows will work on the 64-bit version of Windows.)
Device drivers designed for the 64-bit version of Windows won't work on computers running a 32-bit version of Windows. To learn how to check for drivers, see Update a driver for hardware that isn't working properly or go to the device manufacturer's website.