You can try searching for a file called mplayer2.exe
When you find it right click on one of the files you want to open, choose
open with and locate the program mplayer2, then check the box marked "Always
use this program to open this type of file"
I don't know if that's really what you want but it seems to work here if you
don't want all the bells and whistles that come with Media Player 9.
Please let me know if this works because I have been playing with some
software that needed to restrict the control a user might have over WMP9 and
I'd be interested to hear your results.
Email address should work but the info might be useful to others on here
too.
Charlie