How to determine whether a computer is running a 32-bit version or 64-bit version of the Windows operating system

Use the following methods to determine which version of Windows is installed, as appropriate for the operating system that you are running. 

Windows 8

There are two methods that you can use to determine whether you are running a 32-bit or 64-bit version of Windows 8. If one method does not work, try the other method. 

Method 1: View the System window in Control Panel

1. Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.
2. Type system in the search box, and then tap or click Settings.
3. Tap or click System.
4. If you are running a 64-bit version of Windows 8, 64-bit Operating System is displayed in the System type field under the System heading. If you are running a 32-bit version of Windows 8, 32-bit Operating System is displayed in the System type field under the System heading.

Method 2: View the System Information window

1. Swipe in from the right edge of the screen, and then tap Search. Or, if you are using a mouse, point to the lower-right corner of the screen, and then click Search.
2. In the search box, type system information.
3. Tap or click System, tap or click System Information, and then click System Summary.
4. If you are running a 64-bit version of Windows 8, x64-based PC is displayed in the System type field under theItem heading.
   If you are running a 32-bit version of Windows 8, x86-based PC is displayed in the System type field under theItem heading.  

If you cannot determine whether the computer is running a 32-bit or 64-bit version of Windows 8 by using these methods, go to the "Next Steps" section.

Windows Vista or Windows 7

If you have Windows Vista or Windows 7, there are two methods to determine whether you are running a 32-bit version or a 64-bit version. If one method does not work, try the other method.

Method 1: View the System window in Control Panel

1. Click Start
   
   , type system in the Start Search box, and then click system in the Programs list.
2. The operating system is displayed 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: View the System Information window

1. Click Start
   
   , type system in the Start Search box, and then click System Information in the Programs list.
2. When System Summary is selected in the navigation pane, the operating system is displayed 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.

If you cannot determine the operating system bit count by using these methods, go to the "Next Steps" section.


Video: How to determine whether you are running a 32-bit or a 64-bit edition of Windows

Windows XP

If you have Windows XP, there are two methods to determine whether you are running a 32-bit version or a 64-bit version. If one method does not work, try the other method.  

Method 1: View the System window in Control Panel

1. Click Start, and then click Run.
2. Type sysdm.cpl, and then click OK.
3. Click the General tab. The operating system is displayed as follows:
   • For a 64-bit version operating system, Windows XP Professional x64 Edition Version < Year> appears under System.
   • For a 32-bit version operating system, Windows XP Professional Version <Year> appears under System.
   
   Note <Year> is a placeholder for a year.

Method 2: View the System Information window

1. Click Start, and then click Run.
2. Type winmsd.exe, and then click OK.
3. When System Summary is selected in the navigation pane, locate Processor under Item in the details pane. Note the value.
   • If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of Windows.
   • If the value that corresponds to Processor starts with IA-64 or AMD64, the computer is running a 64-bit version of Windows.

If you cannot determine the operating system bit count by using these methods, go to the "Next Steps" section.

Windows Server 2003

If you have Windows Server 2003, there are two methods to determine whether you are running a 32-bit version or a 64-bit version. If one method does not work, try the other method.

Method 1: View System Properties in Control Panel

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

Method 2: View the System Information window

1. Click Start, and then click Run.
2. Type winmsd.exe, and then click OK.
3. When System Summary is selected in the navigation pane, locate Processor under Item in the details pane. Note the value.
   • If the value that corresponds to Processor starts with x86, the computer is running a 32-bit version of Windows.
   • If the value that corresponds to Processor starts with EM64T or IA-64, the computer is running a 64-bit version of Windows.

If you cannot determine the operating system bit count by using these methods, go to the "Next Steps" section.

Notes

• To find the computer’s bit count, see the documentation that was included with the computer or contact the hardware manufacturer.
• Intel Itanium-based computers can run only 64-bit versions of Windows. Intel Itanium-based computers cannot run 32-bit versions of Windows. Currently, 64-bit versions of Windows run only on Itanium-based computers and on AMD64-based computers.