Problem with media player

Hello

I have dell inspiron 8600. I am trying to play a 25 min video file on it. But it is getting hanged again and again. Media player plays the file for say 10 min. and then it stops. Also it shows the 25 min file as 13 hour file. Same problem comes with real player also. Small files say upto 1 or 2 min are being played properly.

I am using latest version of the media player and real player. The movie file is in .mpg format.