How to determine whether a computer is running a 32-bit version or 64

Determine the operating system bit count

Locate the operating system that is running on your computer in this section, and then follow the steps to determine the bit count of your operating system. To have us help you determine your version, go to the "Fix it for me" section. If you’d rather determine the version yourself, go to the "Windows Vista or Windows 7" section, the "Windows XP" section or the the "Windows Server 2003" section.

Fix it for me

To fix this problem automatically, click the Fix this problem link. Then click Run in the File Download dialog box, and follow the steps in this wizard.

Note This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.

Note If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD so that you can run it on the computer that has the problem.

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 or a 64-bit version. If one does not work, try the other.

Method 1: View System window in Control Panel
Click Start  
 type system in the Start Search box, and then click system in the Programs list.
The operating system is displayed as follows:

For a 64-bit version operating system: 64-bit Operating System appears for the System typeunder System.

For a 32-bit version operating system: 32-bit Operating System appears for the System typeunder System.

Method 2: View System Information window

Click Start   , type system in the Start Search box, and then click System Information in thePrograms list.
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 with these methods, go to the "Next Steps" section.

Windows XP
If you have Windows XP, there are two methods to determine whether you are running a 32-bit or a 64-bit version. If one does not work, try the other.
Method 1: View System Properties in Control Panel
Click Start, and then click Run. Type sysdm.cpl, and then click OK. 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  appears under System.
Note  is a placeholder for a year.

Method 2: View System Information window
Click Start, and then click Run.
Type winmsd.exe, and then click OK.
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 ia64 or AMD64, the computer is running a 64-bit version of Windows.

If you cannot determine the operating system bit count with 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 or a 64-bit version. If one does not work, try the other.

Method 1: View System Properties in Control Panel
Click Start, and then click Run.
Type sysdm.cpl, and then click OK.
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 System Information window
Click Start, and then click Run
Type winmsd.exe, and then click OK.
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 ia64, 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.