: The 64-bit version includes the WoW64 subsystem, allowing it to run most 32-bit applications without modification.

: The most widely compatible version, stable for most legacy hardware. It is limited to addressing a maximum of 4 GB of RAM .

Windows XP Professional remains a cornerstone for software preservation and running legacy applications that require a lightweight, 32-bit or 64-bit environment. Whether for nostalgia or specific professional needs, understanding the distinctions between its primary architectures is essential for a stable installation.