As we had already told you that Microsoft will release next update, Mango, for its Windows Phone 7 by the end of this year, after getting this update users can do many new things and it will feature many updates.
Now jaycee13 at DA has created a theme which is inspired by WP7 Mango and Xbox, Once you install Theme you will get Mango and Xbox like UI on your Windows 7.
After downloading and applying all components of this pack you will see lots of changes on your Windows 7 and you will feel like using Xbox, see screenshot below :-
You can download it from below link :-