Is my PC running the 32-bit or 64-bit version ofWindows?

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 the 32-bit version. Follow the steps in the sections below to find out if your PC is running the 32-bit or 64-bit version of Windowsand what edition of Windows is on your PC.

Computers running 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 ofWindows 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.

Computers running Windows Vista or Windows 7

·         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 underWindows edition near the top of the window.

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