Well, here's the short of it, I have updates done constantly, so that isn't the issue....I have been told before it may have something to do with 'Codecs', but that is something I am not familiar with. So my question is this: How do you know if you are missing codecs and what do you do to tell if and what you need?
In regards to the other respondents question to me....Windows Media Player doesn't even recognize the drive that I put the dvd in to play; and the error message that I get in Windows Media Center is simply "Windows Media Center cannot detect a video dvd in the dvd-rom drive. Insert a video dvd in the drive."
I can't remember when this issue started up, like I mentioned in my original post, it used to work just fine. I have no idea what caused it to stop working.
I will try the suggestions in the post from 'Saurabh A'