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

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 the 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 IA-64, the computer is running a 64-bit version of Windows.