If you only want to disable its internet plug-in (in favor of using Windows Media Player's plug-in) then go to Apple menu > System Preferences > Flip4Mac WMV > Plug-in and uncheck "Use Flip4Mac WMV Internet Plug-in" which disables the Flip4Mac plug-in and enables the WMP plug-in (in /Library/Internet Plug-ins.) The option is only available if you have both installed.
Thanks Julie Julie Julie - now my $2000 PowerBook can view video again.
Since I'm not on Tiger yet, I still get to use that ANCIENT old fossil Windows Media Player and - would you believe it!? - IT WORKS!!
"One step forward - two steps back." These are awkward times for anyone who expects to watch video on a $2000 machine.
Seriously, thanks julie julie julie. I wanted that old WMP back ever since I installed that woeful dog Flip4Mac and now I've got WMP up and running again.
I should also note that Flip4Mac broke the video in the greatest news website on Earth - BBC News.
The solution is for video content providers to author their video in the new Flash Pro 8 video player. I bet aliens from another planet could watch Flash video without any platform incompatability.