How to remove XP beta SP2 ID from desktop?

A number of months ago I installed a beta version of Windows XP SP2. I
subsequently uninstalled it but it left behind a "permanent tattoo" on the
bottom right corner of my desktop saying:

Windows XP Professional
For testing purposes only. Build 2600.xpxp2.030422-1633 (Service Pack 1)

I'm sure there is a way to remove this, but I can't seem to find it. I
assume it's buried somewhere in the registry.

Obviously it's not a big deal nor a critical issue for me, but I'd like to
get rid of it.

Thanks for any tips on where to look.

Charles Tomaras
Seattle, WA