WMP won't play quicktime

[stlolth]

I've downloaded some quicktime videos from apple trailers and WMP won't play them.
The windows says "media changing" and the error window claims it's an unsupported codec.

 

[Lemur]

Install the K-Lite Codec Pack and you should be in good shape.
Codec Guide: K-Lite Codec Pack - Windows 7 codecs

 

[Gornot]

As an alternative, you can try installing QT Lite which only includes the codec and MP3 support for web browsers (and websites that actually require you to have QuickTime installed). This way you won't have to burden your system with unneeded codecs and tweaks that K-Lite has.