Windows XP x64 Edition

Microsoft Windows XP Professional x64 Edition, released on April 25, 2005, is an edition of Windows XP for x86-64 personal computers. It is designed to use the expanded 64-bit memory address space provided by the x86-64 architecture.[1]

The primary benefit of moving to 64-bit is the increase in the maximum allocatable random-access memory (RAM). 32-bit editions of Windows XP are limited to a total of 4 gigabytes. Although the theoretical memory limit of a 64-bit computer is about 16 exabytes (17.1 billion gigabytes), Windows XP x64 is limited to 128 GB of physical memory and 16 terabytes of virtual memory.[3]

Windows XP Professional x64 Edition uses the same kernel and code tree as Windows Server 2003[4] and is serviced by the same service pack.[5] However, it includes client features of Windows XP such as System Restore, Windows Messenger, Fast User Switching, Welcome Screen, Security Center and games, which Windows Server 2003 does not have.

Windows XP Professional x64 Edition is not to be confused with Windows XP 64-Bit Edition as the latter was designed for Itanium architecture.[6][7] During the initial development phases, Windows XP Professional x64 Edition was named Windows XP 64-Bit Edition for 64-Bit Extended Systems.[8]