MCE has a built-in content protection feature that prevents protected files from playing on other PC that did not originally record the content. You can only watch them from Media Center on the Media Center PC that originally recorded it.
Some movies or TV shows are marked as protected when they are recorded. Because of this, you may not be able to add them to a CD or DVD. The terms of the content protection are determined by the content owner, broadcaster, or originator. For example, you may not be able to burn some shows or movies that you recorded from a premium channel to a DVD that you can play on other DVD players. Instead, you may need to back up shows that you recorded from premium channels onto data DVDs that will play from your Media Center computer.