Trying to play certain video files in different viewers (IrFanView for starters) and some won't open because a certain Codec is missing. Others with that same extension will play.
How do you determine what Codec is needed with a given file before you try to open it other than looking at the file extension?

Google for a program called GSpot. It'll identify what codecs you need to play a video file and it also tells you other things about the file like wether it's complete or not.

Thanks............

Gracias ... I myself was wondering this

Gracias ... I myself was wondering this