Codec problems
 

I opened up said video file and it said I needed to download a codec for it, so I did. Now it plays but without sound and it says error downloading codec right before it plays.

What type of video file is it?

Video Clip it says under prroperties.

No no no, he means .avi,.mpg,etc. That's video file type.....*rolls eyes*

Downlaod the Ace Mega Codec pack, works for like everything and then get VLC Media player. Search those in google and you will/should find them.

Divx

Hit the download button and when it's done, only install the Divx codec, uncheck every other box. Otherwise you'll have a shitload of Divx stuff on your computer, but the codec is good and works with any media player.... Heh, I just upgraded my WMP today and needed it to play a 30 minute MegamanZero Speedrun(Damn, that guy has SKILLS!)