Seems like WMP11 comes with SP3. That means WMP10 is never installed on this XP SP3 OS. Is there any way to downgrade it back to WMP10? Thanks!
EDIT: I am getting this error message no matter when trying to install WMP10. I've tried to reinstall/uninstall WMP11 but still can't fix this. Is there any place in registry that can fix this? I suspect this is not directly related to WMP registry but some dependency stuff like DRM. Thanks!