Know whether you are using 32-bit or 64-bit edition of Windows 7

Windows 7 comes with 32-bit and 64-bit editions. You can have either 32-bit or 64-bit edition installed depending on the type of processor that you have. To know which edition of Windows 7 is installed on your computer, perform the following:
1. Click Start button , right-click Computer and click on Properties to view basic information about your computer.
2. Under System, see the information to the right of System type:. It will be mentioned as 32-bit Operating System or 64-bit Operating System.

You may also press and Pause Break keys to view basic information about your computer.