Win64

Win64 refers to the 64-bit edition of the Windows operating system family that runs on x86-64 processors, also known as AMD64 or Intel 64. It provides a 64-bit kernel and user-mode environments, enabling native execution of 64-bit applications and a much larger virtual address space than 32-bit Windows. The x86-64 architecture retains backward compatibility with 32-bit code, allowing 32-bit applications to run on 64-bit Windows through a compatibility layer known as WOW64.

Key characteristics of Win64 include a substantially larger address space, improved performance for many workloads, and enhanced security features such as Data Execution Prevention, Address Space Layout Randomization, and other kernel protections. Hardware requirements include a 64-bit-capable processor and a 64-bit edition of Windows. In practice, Windows consumers use Windows 64-bit editions of Windows 10 and Windows 11, while servers use corresponding 64-bit server editions. The exact memory and feature limits depend on the edition and hardware.

Software compatibility on Win64 differs from pure 32-bit Windows. Native 64-bit applications run directly in 64-bit mode, while most 32-bit applications continue to run via WOW64. Some legacy 16-bit Windows applications are not supported on modern 64-bit Windows. Device drivers must be 64-bit; 32-bit drivers are not compatible with 64-bit Windows.

History and usage: 64-bit Windows began with early 64-bit editions such as Windows XP Professional x64 Edition and Windows Server 2003 x64. Since then, 64-bit Windows has become the standard for desktop and server deployments, with most software and hardware ecosystem support prioritized for 64-bit operation.

See also: x86-64, AMD64, Intel 64, WOW64.