If your goal is to fully update a 64-bit XP installation, you should download . This is the official "SP3 equivalent" for your operating system. Final Official Service Pack Core Kernel Version Windows XP (32-bit) Service Pack 3 (SP3) Windows XP (64-bit) Service Pack 2 (SP2) Official Download Links

You can still find the official installers through Microsoft's legacy portals:

The confusion stems from the fact that Windows XP Professional x64 Edition is fundamentally different from the standard 32-bit XP.

The final official service pack for Windows Server 2003—and therefore for Windows XP 64-bit—is Service Pack 2 (SP2) . What to Download Instead

Because it shares its "DNA" with Server 2003, XP 64-bit uses Server 2003 service packs.

While Windows XP 32-bit (the most common version) received SP3 in 2008, the 64-bit edition followed a completely different development path. To keep your system fully updated and secure, you must use the correct final service pack designed for your architecture. Why SP3 Doesn't Exist for 64-Bit XP