If you are looking to customize Windows Media Center then you can try out Media Center Studio. It is a freeware application for Windows 7 and Windows Vista that enables you to customize Windows Media Center. It supports theme application and editing.

Features of Media Center Studio

• You can edit the start menu by rearranging or disabling native menu items
• Create your own menu strips and your favorite items to go in them
• Monitors your application and returns to Media Center when it exits
• Set up a button on your remote to exit your application
• Create menu items that take you to native Media Center pages, or start media
• Apply your own themes to Media Center
• Create new themes or edit existing ones very easily

Download Media Center Studio