I moved a video from the SD from my cellphone, onto my laptop. It lost ALL of the sound. Is there a reason for this?

Maybe it didn't lose the sound but your player on your laptop doesn't have the right audio codec to play it? Also, you might need to convert it from 3GP to AVI/WMV format. (depending on the type of Phone)

There are mobile media codes available through VLC and you can Google 3GP-AVI/WMV converters!

I have no idea either lol. It's a video that came from my blackberry phone. It was saved onto the mini SanDisk, then I moved it to my laptop. I tried playing it in windows media player, and windows live movie maker. But neither had sound just the video. Ill try to find VLC

Google is yor best friend when dealing with this. Because somewhere out there someone as done this!