How can I get my windows media player to work?

Sounds like a stupid question, because its something that just works on any computer with Windows installed , without anyone doing anything.

But when I try to play a video that's vital to my job, an error message comes up that says something about a missing 'codeq' that's not installed on my computer. Now, I know for a fact that I've been using that media player like crazy during the two years I've had this computer with no problem, so how is it all of a sudden there's a missing component?

So, anyway, I go looking for the missing 'codeq', and there's some hairy, indecipherable process involved in identifying a specific missing codeq for a specific model of computer and OS.

Then, I think maybe I'll just uninstall and then reinstall the whole media player and that might solve the problem. But the media player isn't listed on the list of programs that comes up when I go into the control panel under 'uninstall programs'. so, I just go online and find the media player install anyway, but when I try to download it, I get "a more recent version already exists on your computer. You can't install an older version to replace or repair a newer one".

So I'm stuck with a media player that doesn't work, and a link to video from a job training site I can't play. It only asks for window media player - I thought about trying to play it on another type of media player.

Any suggestions from the resident brains?