Reinstall Media Player and Media Center

Hi, I have beginning to have issues playing DVDs on my Inspiron 531. If I play a DVD using Windows Media Player and Windows Media Center I get color staticy video. All my Video drivers and CDROM Drives are updated and reinstalled. I think this problem is an software issue and I would like to reinstall Windows Media Player and Windows Media Center. How do I do this?

               Thank you for any replies

  My Computers:
Desktops:
-Dell Inspiron 531 - AMD Dual Core 4400 - Windows Vista Home Premium
Notebooks:
-Dell Inspiron 1000 - Intel Celeron - Windows XP Home Edition
-Dell Inspiron E1505 - Intel Centrino Duo - Windows XP Media Center Edition