Removing movie folders from Windows Media Center

I recently removed numerous media folders, that I have on an external hard drive. I replaced my old computer with a new one. Now I want to add these folders again. But Windows Media Center is showing 2 occurances of each movie folder. Can I get Windows Media Center to remove all traces of the old folder locations. Thanks

I followed the tutorial you sent me. But it didn't work. The duplicate movies titles are showing up on my laptop that is remotely connected through my network. When I try to add movie titles from the hard drive (located on another computer) I have two names of the same title. Sorry, I should have mentioned that before.