I don't know which codec to download

I am trying to play videos from my digital video camera and it will not play on my computer. It tells me that I need a video codec but I don’t know which one to download. Please help!!!!

I recommend first identifying what codec is needed. Try GSpot for this:
http://www.headbands.com/gspot/
Direct download - http://www.headbands.com/gspot/gspot221.exe