BleepingComputer.com: Media Center Skipping Problem

I am running a Windows Vista Media Center PC. I frequently use my built in TV tuner. Recently whenever I open up Media Center to watch my recorded shows it is very slow to respond. The small opening scene that shows whenever you open the program skips constantly. I then click on recorded TV and it takes at least 30 seconds to load. When it finally loads I get the preloaded programs that came with the computer, Appolo 13 preview and the tropical fish. I cannot delete these programs, it says the show may be read only. I initially deleted these shows when I got my computer a few months ago and I have no idea why they are showing up now. Sometimes when I load Media Center it says no shows recorded, sometimes the most recently recorded shows will appear like they have been recorded twice, sometimes a couple shows will come up as a black screen with no name. When I do click on a show, it doesn't matter if the show was recorded before or after this problem occured, the show plays for about two seconds and then freezes. Live TV also has the same problem. When I play the recorded shows on Windows Movie Maker they work fine, so I know the problem is with Media Center not with the recordings. Does anyone have any idea about what could be causing this problem, or have any ideas about how to fix this problem. I have recorded shows on both my internal hard drive and an external hard drive. This setup did work fine until this happened. I thought maybe it was having trouble reading off of the external hard drive but even when I disconnect it the problem still continues. I am sorry this post is so long and it probably is pretty confusing, but any help fixing this would be greatly appreciated. Thank you all in advance.