Over the past few years, I’ve done a lot of presentations on x64 technology as it pertains to game developers and DirectX technologies. Here is a collection of links for developers interested in learning more about the Windows x64 OS and x64 native programming generally.
64-bit programming for Game Developers (DirectX SDK)
RAM, VRAM, and More RAM: 64-Bit Gaming Is Here (Gamasutra)
64-bit Gaming Is Here Today - Where Are You (Gamefest 2008) link
Why Your Windows Game Won’t Run In 2,147,352,576 Bytes (Gamefest 2007) link
Game Development for 64-bit and Understanding 64-bit Development (Meltdown 2005) link
Windows Server is only available for x64 native as of Windows Server 2008 R2.
Note that Windows 11 is only available for x64 native or ARM64. There is no 32-bit (x86) version of Windows 11.