Web Radio streaming problem with Vista / Media Player 11

I've been asked to sort out a Samsung laptop running Vista which has a
problem streaming audio from web radio stations. It can stream those
broadcasting in "realplayer" format OK, but anything in WMP format is a
problem. It worked until around three weeks ago, now it just gives a "missing
codec" error
I've tried syste restore, no joy. I tried ading the K-lite codec pack, no joy
Basically I need to reinstall the WMP codecs. Reloading the PC is NOT an
option
Any ideas please?
An example of one of the radio stations involved is

http://www.midwestirishradio.com/mwr/index.php