GPMC doesn’t run on 64-bit Windows
Microsoft’s Group Policy Management Console (GPMC) is a useful tool to manage Group Policies in Active Directory. However, unfortunately GPMC does not run on certain 64-bit Windows operating system, such as Windows Server 2003 and Windows XP. GPMC only runs on:
1. 32-bit Windows Server 2003
2. 32-bit Windows XP Professional with SP1 or later and .NET Framework
Microsoft has not updated GPMC in almost 3 years. The current download for GPMC was published in June 2004. If you have a pure 64-bit Windows Server 2003 environment, you might want to consider installing GPMC on a 32-bit Windows XP Professional.