X64

Windows XP Professional x64 Edition (NT 5.2.3790) is an SKU of Windows Server 2003 x64 which was designed for the typical, non-server consumer (hence the XP moniker). Using it is weary, given the patchy driver support and the rather 'preliminary' WoW64 emulation that is provided in the core.

Not to be confused with 64-Bit Edition which was designed for the pure 64-bit Itanium IA-64 instruction set.

The ISO for the AMD64 version discussed here, on MSDN, uses 'en_win_xp_pro_x64*', and was released in retail and volume - later on with SP2 - while the other one uses 'en_winxp_pro_64bit' and never received a service pack.

Known Working Native/AMD64 Software

 * MyPal (v28.10.0 tested)
 * roytam1 browser family (No specification of version is required)
 * VLC Media Player (v3.0.11 tested)
 * RetroArch (v1.8.9, MSVC 2010 tested)
 * Snes9x (1.60 tested)
 * FCEUX (builddate 12-7-2020 tested)

''Feel free to add to this list, it's a stub right now pretty much as I don't have too much to test right now. I know qBittorrent and PuTTY don't work (though the respective x86 versions did, simply throwing a Win32 invalid application error.''

Advantages over XP x86

 * Full 4GB+ RAM support without screwing about with re-establishing PAE in SP3.
 * Still runs relatively lightweight at idle in comparison to XP x86 on the same hardware. This is in stark contrast to say, Windows 7.
 * Can be installed in UEFI non-CSM mode somehow. I haven't tried this.

Known Limitations

 * Rather patchy driver support, especially for periperals.
 * Office 2010 refuses to install regardless of whether you try to install in x86 or x64 mode.
 * TLS 1.1 and 1.2 patches don't exist for WS2003, therefore they don't exist for XP x64 either.
 * Info pertaining to x86 XP does not generally cater to x64 XP if you're modifying files or the like. If advice for Server 2003 is given however, follow that instead.