What does WMP9 need to play MP4

I have installed WMP9 on Windows 7 but found out i can play WMV files no problem but cannot play MP4 files is there anything i can do to play MP4 files ?
Thanks

Codecs

I have got codec installed but get the messsge
'The selected file has an extension that is not recognized by the windows media player'

The installation process for K-LITE should handle the file association for you.

Thank you but now i have the problem where the seek button does not work any ideas ?

I use the 64bit version of Media Player Classic (which is offered with the K-LITE install) because that player lets me step thru videos frame by frame. In that player, the seek bar's usefulness seems to be a function of the file being played. The seek bar does work from some MP4 files - but not for others :-(

Someday, I should probably use QuickTime to test one of the MP4 files where the seek bar fails while using other players.

so there is no definitive way of wmp9 fuctioning properly on windows 7 ?

I have not found a way to get any version of WMP (or any other player) to always seek properly on every file.

Ok thanks

Is there a reason for using WMP9 ? IIRC it dates back to 2003. Current version is WMP12, which plays mp4 fine.

For anything that won't play on WMP12, I use VLC. I've had problems with 3rd party codec packs in the past, mainly changing file associations and screwing the OS in general. VLC has its own codecs and doesn't change anything in the OS.

VideoLAN - VLC: Official site - Free multimedia solutions for all OS!