Here are some Windows 7 Gears of War themes from Microsoft –old and new :
Gears of War 3 Launch theme
Celebrate the launch of the latest installment in the Gears of War series for Xbox 360 with this free Windows 7 theme, featuring glorious images from the savage, fantastical world of the all-new Gears of War 3.
Gears of War 3 Delta Squad theme
These characters are as tough as they come. Marcus Fenix, Dominic Santiago, and the other heroes of Delta Squad come to life on your Windows 7 desktop with this free theme for Gears of War 3.
Gears of War 3 theme
Prepare your desktop for battle with this free Windows 7 theme containing portraits of Marcus Fenix, Dominic Santiago and Anya Stroud from Gears of War 3.
Here are some Gears of War themes released earlier -
Gears of War 2 theme
Put Marcus Fenix and Delta Squad right on your Windows 7 desktop with these free blazing stills from the Xbox blockbuster.
Gears of War theme
Your desktop becomes a post-apocalyptic doomscape where the Delta Squad, armed with chainsaw bayonet-mounted assault rifles, battles the subterranean Locust Horde. This free theme for Windows 7 includes detailed shots of Ben Carmine, Dominic Santiago, and other Squad members from the hit Xbox and PC game, plus conceptual artwork and stills from the "Mad World" television commercials.
For more such cool Windows 7 themes please check http://windows.microsoft.com/en-us/windows/downloads/personalize/themes