.mov file has a black screen AND no sound.

I’m just trying to play a .mov file from a school website. Other computers are able to get it but none of mine can and I own 5 of them. I’m guessing that I have a program that interferes with this program or something because I’ve tried to download codecs to no avail. Can someone help me get this video and audio feed? Thanks.

I have a PC on Vista and a PC on XP and a Safari on Mac. None of these computers are able to play the .mov file which others are able to...I just get a black screen WITH no sound.

Can you follow the steps on this page and report what the codecs are? Perhaps you’re missing the decoder in the first place.
Your post is weird, because normally when the decoder is missing, you’ll get a white screen. Perhaps, if you go into the advanced settings and turn off hardware acceleration it might resolve things. It’s in Edit, Preferences, QuickTime Preferences, Advanced. Turn on and off the check marks under DirectX one at the time in various combinations and see if anything gives (there’s 8 combinations total) - pick the combo that works, but has the least features turned off (because turning off hardware acceleration tends to take a hit on performance). If all combos fail, then switch to 'Safe mode (GDI only)'.

If this fails, turn to VLC Media Player. In the past I’ve held back about recommending it because QuickTime Player is the “official” player for .mov files (it’s Apple’s format), but lately VLC’s performance at playing back .mov files eclipses QT’s.