Do I need a Hard Drive or Memory Unit to used Windows Media Center?
Windows Media Center does not require a hard drive or memory unit for the Xbox 360 console. Windows Media Center does not copy content from your Windows Media Center-based PC to the Xbox 360 console. Media content streams from the PC to the Xbox 360 console, much like Internet radio station streams music to your PC. When you use your Xbox 360 console to play content, your digital media files and pictures remain on your computer.