Problems with the CASIO EXILIM EX-Z80?

so. i have this camera. i record videos on it and when i upload them on the computer. it does not show up. i dont know why. i uploaded videos on my dads sony cybershot camera and it does show up on the computer. ive tried uploading videos from the casio camera on 2 different computers thinking maybe theres something wrong with the computers but it still does not show up. i mean it does show up. i can hear the sound but not the picture.. help please!