We would like to extend an invitation for you to beta test a version of Windows Server 2003 SP1 and Windows XP Professional for x64 processors.
This service pack beta is really two programs in one. First it is a traditional service pack that contains fixes and security enhancements for Windows Server 2003. It is also a new client release of Windows XP Professional that is designed to run on AMD Athlon 64 and Opteron processors and Intel processors with EM64T.
Regardless of whether you wish to test just the server or the new 64-bit client, we welcome you to join.
News source: Beta Place