Select a Software Platform: 32-Bit or 64-Bit

For more information about 32-bit and 64-bit Windows 7, see 32-bit and 64-bit Windows: frequently asked questions on Microsoft.com.

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.

To find out which version your computer is running, do the following:

Windows XP
For Microsoft® Windows® XP:

• Click Start, right-click My Computer, and then click Properties.
• If "x64 Edition" is listed under System, you’re running the 64-bit version of Windows XP.
• If you don’t see "x64 Edition" listed under System, you’re running the 32-bit version of Windows XP. The edition of Windows XP you're running is displayed under System near the top of the window.

Windows Vista or Windows 7
For Microsoft® Windows Vista®:

• Click the Start button, right-click Computer, and then click Properties.
• If "64-bit Operating System" is listed next to System type, you’re running the 64-bit version of Windows Vista or Windows 7.
• If "32-bit Operating System" is listed next to System type, you’re running the 32-bit version of Windows Vista or Windows 7.

The edition of Windows Vista or Windows 7 you're running is displayed under Windows edition near the top of the window.