from http://support.microsoft.com/kb/827218
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 (year) 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 ia64 or AMD64, the computer is running a 64-bit version of Windows.
Program Files (x86)
folder. If there is, that's 64-bit Windows.