Determining whether 32 bit or 64 bit Windows....

HOW TO: Determine Whether Your Computer Is Running a 32-Bit Version or 64-Bit Version of Windows XP

SUMMARY

This step-by-step article describes how to determine whether a computer is running a 32-bit Microsoft Windows operating system or a 64-bit Microsoft Windows operating system. 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.

Note Intel Itanium-based computers can only run 64-bit versions of Windows. Intel Itanium-based computers cannot run a 32-bit Windows operating system. Currently, 64-bit Versions of Windows only run on Itanium-based computers.

Use My Computer to Check System Properties

1. Click Start, right-click My Computer, and then click Properties.
2. In the System Properties window, click the General tab.
3. Note the first line under Computer: • On 64-bit systems, Itanium or Itanium 2 appears on this line.
• On 32-bit systems, a value other than Itanium or Itanium2 appears on this line.

Use the Winmsd.exe Tool to Check the System Type

1. Click Start, and then click Run.
2. Type winmsd.exe in the Open box, and then click OK.
3. Locate System Type in the right pane under Item. Note the value. • If the value that corresponds to System Type is X86-based PC, the computer is running a 32-bit version of the Windows operating system.
• If the value that corresponds to System Type is Itanium–based system, the computer is running a 64-bit version of the Windows operating system.


Use the Winmsd.exe Tool to Check the Processor

1. Click Start, and then click Run.
2. Type winmsd.exe in the Open box, and then click OK.
3. Locate Processor in the right pane 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, the computer is running a 64-bit version of the Windows operating system.

.....This article is from Microsoft Website.....
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APPLIES TO
• Microsoft Windows XP Professional
• Microsoft Windows XP Tablet PC Edition
• Microsoft Windows XP Media Center Edition 2002
• Microsoft Windows XP Home Edition
• Microsoft Windows XP Professional 64-Bit Edition (Itanium)
• Microsoft Windows XP Professional 64-Bit Edition (Itanium)
• Microsoft Windows XP Professional 64-Bit Edition (Itanium)