What codec is needed for a Video File I have
If you have a complete video file and it will not play, it is typical that the problem is the lack of the proper codec (compressor/decompressor) to play the file.
So to eliminate this as an option, or to find what codec you need to install.
Get Gspot from here
Open the video file in question, it will tell you what codec it was encoded with, what codec it is being played with, and whether the proper codec is installed.
For all your specific codec needs go here.