Now that Angry Birds is officially available for Windows and also Windows Phone 7, Microsoft has now released the Angry Birds theme for Windows 7. The Angry Birds theme for Windows 7 comes with wallpapers based on the game. The theme comes with 5 wallpapers and what makes the theme better is the notification sounds. The sounds are perfectly matched from the original game.
You can also try out the unofficial Angry Birds theme for Windows 7.