Didn't even know that this exists. Shame on me.

From the abstract: "This document provides information regarding features in Windows XP Professional x64 Edition that differ in functionality from Windows XP Professional Service Pack 2 (SP2). It is important to note that this document uses the Windows XP Professional SP2 feature set as the baseline for comparison with Windows XP Professional x64 Edition. Features not documented here are at parity with Windows XP Professional SP2 and function the same way."