This is the ONLY codec type appliance you will need.
Forget about all of those codec incompatibility problems and forever wondering what you need to play a film you downloaded and it has no sound or the picture is bad or not working. Ffdshow will play just about anything and it allows it to be played in your favourite player too.
I recommend Media Player Classic which works really well with it but all players I have tried work with it. Your worst one would have to be windows media player.
Highly recommended software and being updated all the time...just keeps improving!

for best results get the CCCP-project.net flavor of ffdshow

the output options are ALL under your control! Dark scnese? boost opacity and gamma to YOUR preference. Save as many output schemes as you please for those ahem TV xvids you have, or your DVD vobs, to your SVCDs, or God forsaken 'Real'media files.

The beauty of FFDShow isn't that it can decode DIVX, although it can. The beauty isn't that FFDShow can decode almost any audio or video you throw at it, although it will. No, the true beauty lies in its ability to perform audio, but more importantly, video post-processing. Blocky video? Deblock it. Too dark? Normalize the luminence. Pesky logos from the Web site you ripped the video from? Integrated logo removal. Perspective wrong, noisy, interlaced, aspect ratio off, just about any problem your video has FFDShow has a setting that can help. Don't think. Download.