Windows 7 - Windows Media Player and VLC

I apologize if this has been addressed elsewhere or if I am in the wrong area or if this is just a dumb question! I downloaded Windows 7 about a week ago, before then I was able to play dvds and downloaded movies just fine. After downloading Windows 7, I am unable to play a DVD in Windows Media Player... it just keeps says play dvd, I will click it, it'll refresh and say play dvd again, over and over. I went to the library to click on a specific chapter and it would not play that either. Then I decided to try it in VLC player. VLC works just fine playing the video.. but there is no sound! And I know I am not on mute and my volume is turned up! I am really bad with all of this computer stuff.. Does somebody know how to help me out? Thank you very much.

you may need a codec to make Windows Media Player play videos, see here:
Win7codecs

Thanks for the headsup, buddy! Shark007 is great!