Found this a few days ago:
Desktop Backgrounds for Windows
Microsoft New Zealand is making available some free desktop backgrounds for use on your computer. Includes the New Zealand version of Bliss; the world-famous directional sign in Bluff; and the theme pack for Royale. Check back each month as we add more!
Preview & Download
Direct download (Royale.zip)
I was bored of the default XP theme, so it looks good for a change