First, check your version of the WMP against the latest upgrade of it and if it isn't the latest, try the Windows Update to make it so. Reboot and test again.

Realtek and ASIO4ALL. You might have the settings in the ASIO4ALL control panel such that the soundcard won't be shared with another audio host when one is open and already addressing the card. This may also be a setting within RealBand's Prefs -> Audio, too.


--Mac