I haven't used my BIAB in several weeks. today I come back to it and I can only get drums to make any sound.

I'm using an external USB soundcard. settings on ASIO or MME make no difference.
MIDI output = coyote or MS GS Wavetable - no difference
no instruments are muted or solo'd in the mixer.

if I open the STYLES dialog box and play the "Quick Play" then ALL INSTRUMENTS PLAY.
but once I leave the style picker and try to play a song, only drums!

I tried resetting to factory settings also, that didn't help either.

any ideas?

nevermind. I figured it out. I had my USB drive turned off. it couldn't load the real tracks.

Hah! That would do it.

On occasion, I mute my sound card, and then I forget that I did that, and later wonder why no sound is coming out.

Glad you figured it out.