guys, someting is wrong with my computer, everytime i click a media file like play music or video on my media player i get this error "Windows Media Player cannot play the file because there is a problem with your sound device. There might not be a sound device installed on your computer, it might be in use by another program, or it might not be functioning properly." but I have sound when opening folders and when i turn off and turn on my computer, but when Im using media player, I get no sound...pls help