The 64-bit versions of the Windows Editions will be labeled by one of two tags to distinguish Microsoft 64-bit Windows versions from one another.
The two tags are:
For 64-Bit Itanium-Based Systems
For 64-bit Extended Systems
The term "64-bit Extended Systems" refers to processors that have added 64-bit extensions to the 32-bit instruction set, such as AMD Opteron and AMD Athlon64 processors. Windows Server 2003 editions will use "64-bit Extended Systems" to denote offerings for 64-bit AMD processors instead of the terms x64, x86-64, or AMD64.
The 64 bit Windows will be named as the following:
Microsoft® Windows ServerTM 2003, Standard Edition For 64-Bit Extended Systems (will RTM with SP1)
Microsoft® Windows ServerTM 2003, Enterprise Edition For 64-Bit Extended Systems (will RTM with SP1)
Microsoft® Windows ServerTM 2003, Standard Edition For 64-Bit Itanium-Based Systems (will RTM with SP1)
Microsoft® Windows ServerTM 2003, Enterprise Edition For 64-Bit Itanium-Based Systems (available today)
Microsoft® Windows ServerTM 2003, Datacenter Edition For 64-Bit Itanium-Based Systems (available today)
Microsoft® Windows® XP 64-Bit Edition For 64-Bit Extended Systems (will RTM with SP1)
Microsoft® Windows® XP 64-Bit Edition For 64-Bit Itanium-Based Systems (available today)