Am I using the 32 bit or 64 bit version of Windows?

To determine whether your computer is running a 32-bit Windows operating system or a 64-bit Windows operating system, examine the system information. To do this, use one of the following methods.

For Windows Vista

Method 1:
1. Click Start , type system in the Start Search box, and then click system in the Programs list.
2. The operating system appears as follows:
• For a 64-bit version operating system: 64-bit Operating System appears for the System type under System.
• For a 32-bit version operating system: 32-bit Operating System appears for the System type under System.

Method 2:
1. Click Start , type system in the Start Search box, and then click System Information in the Programs list.
2. The operating system appears as follows:
• For a 64-bit version operating system: x64-based PC appears for the System type under Item.
• For a 32-bit version operating system: x86-based PC appears for the System type under Item.

For Microsoft Windows XP Professional

Method 1
1. Click Start, click Run, type sysdm.cpl, and then click OK.
2. Click the General tab. The operating system appears as follows:
• For a 64-bit version operating system: Microsoft Windows XP Professional x64 Edition Version < Year> appears under System.
• For a 32-bit version operating system: Microsoft Windows XP Professional Version appears under System.

Note Year is a placeholder for a year.

Method 2
1. Click Start, click Run, type winmsd.exe, and then click OK.
2. In the details pane, locate Processor under Item. Note the value.
• If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of the Windows operating system.
• If the value that corresponds to Processor starts with ia64 or AMD64, the computer is running a 64-bit version of the Windows operating system.

For Microsoft Windows Server 2003

Method 1
1. Click Start, click Run, type sysdm.cpl, and then click OK.
2. Click the General tab. The operating system appears as follows:
• For a 64-bit version operating system: Microsoft Windows Server 2003 Enterprise x64 Edition appears under System.
• For a 32-bit version operating system: Microsoft Windows Server 2003 Enterprise Edition appears under System.

Method 2
1. Click Start, click Run, type winmsd.exe, and then click OK.
2. In the details pane, locate Processor under Item. Note the value.
• If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of the Windows operating system.
• If the value that corresponds to Processor starts with EM64T or ia64, the computer is running a 64-bit version of the Windows operating system.