Regrding DVD

Hello,
sir i m sakshi i needed to ask thati have put my Dvd in my computer to watch the movie it is reading the dvd n movie is also playing but i cannot hear what they are saying as there is no volume but i also check my volume as if i came out from ma dvd player n then oterwise play music then it is playing the songs n i can hear everything would jst help me out please its really imp n before u say i also wanted to add when i bought the DVD the shoopkeper played me in his pc to show n it was having sound so plz give me update how can i fix my problem plzzzzzzzzzzzzzzzzzz its a request n mail me at ma email id the one i have already mention above n i do have another which is sakshy.kaul@gmail.com
as soon as possible
thnks
sakshi