Both Windows XP Pro and Windows XP Home Edition are "version 2002". And, just to make things even more confusing, try issuing the "winver" command from the Start|Run dialog. Then you'll see that your Windows XP is also "version 5.1" and "build 2600". RC2 was a pre-release (release candidate) with a build number of 2526.
So, anyway, XP = version 2002 = version 5.1 = build 2600, regardless of whether you're running Pro or HE. I predict that eventually the OS will answer to any name. 😀
- Collin
Edit: Oh, BTW, the corporate versions also answer to the same names.