just a bit of basic explanation - forgive me if you already know this. drivers are litle programs that make hardware work - your printer has a driver and so does your internal soundcard and your external audio interface.

MME is an old fashioned Microsoft Windows driver that works perfectly most of the time with BIAB for playback with internal soundcards so its the 'safe' choice. Trouble is if you want to record audio with MME there's a 'lag' so your recording and playback are difficult to get in synch.

WAS is a newer Microsoft Windows driver that usually works fine with internal soundcards and does not have the lag problem you get with MME so you can record audio in perfect synch.

ASIO is............. "ASIO (Audio Stream Input/Output), developed by Steinberg, is a cross-platform, multi-channel audio transfer protocol that is being adopted by many of the manufacturers of audio/MIDI sequencing applications. It allows software to have access to the multi-channel capabilities of a wide range of powerful sound cards."

in plain english it's a dedicated type of driver designed to be the ideal solution for music making and sound production. however it's a type of driver and not all asio drivers are the same. every manufacturer makes its own ASIO driver using the same standard but designed to work perfectly with its own kit.

that's why the ASIO Realtek driver is different to your Behringer ASIO driver. Just the same as an Epson printer driver is different to a Canon printer driver.

and you choose the driver to use with BIAB within BIAB itself. and bear in mind that BIAB will send the music it generates to either your internal soundcard or your external audio interface. MME and WAS will be your internal soundcard (and if its a REALTEK chip it seems you have a REALTEC ASIO driver but that seems to create problems so its best avoided) when you haven't got the behringer plugged in. If you plug the behringer into USB you should use the Behringer ASIO driver but we don't know if the unit is faulty or not.