How do I disable Windows Media Player 12?

Other way?
You don't need to disable it, just don't use it!
If you don't like it try to use another media player.
Personally I use Media Player Classic and VLC player for video and Media Monkey for audio.
You can choose which program starts automatically when you right click on a media file and select "open with" then "Choose default program".

soop said:

I want to disable it because it eats up all available CPU doing god-knows-what. Not because I don't like it.

That's quite strange. If it's inactive there should only be the WMP Networking service & that uses hardly anything

Unless i'm missing something (i've just check my Task Manager)

You can uninstall it via

Control Panel - Uninstall a program - Turn Windows features on or off - Expand Media Feature - Uncheck Windows Media Player

Edit: Just read your first thread more carefully, you've done this.

Windows Media Center uses Windows Media Player, you can't remove one without the other.

If you have high utilization check your library and streaming settings. If you have WMP updating your metadata it will try and match all your music.

I saw your other thread and it mentioned that your WMP is uses 100% CPU when using your extenders. Is that the only time? If so, what are you doing on the extender?

If you are attempting to watch a movie that the extender does not natively decode then WMP is used to transcode and stream the movie to the extender.

Some things that would help troubleshoot are:

1- System specs, this is on option in your profile and helps others trying to help you.

2- OS Build. 7100 and below had quite a few Media Center related bugs

3- What 3rd party decoders, codecs and such you have installed. If you have a Codec Pack...don't! Some play nicer than others but I wouldn't recommend ANY.

I can try to help further if you provide the above. Thanks