Success! Sort of anyway. After reading some of the threads you guys pointed me to and fiddling around with the driver settings, I was able to get playback sound with ASIO4ALL for the first time. I was also able to record and play back realtime midi input from an external usb keyboard, and the best part is that the latency going in was almost non-existent - certainly very workable. Apparently the Realtek soundcard wants to default to spdif digital outputs. Disabling those forced the sound to the analog outputs.

It's still quite quirky, with occasional crashes and such, but now that I know how to reset RB by deleting the 2 files you pointed out, I'm able to redo the setup so that I can get it working again. Again after reading some of the threads, I think a more permanent solution would have been to get an updated version of the Realtek HD Audio driver, but I downloaded Vista versions from both the Realtek site and from Lenovo and even after following installation instructions both failed to install, so I had to revert back to the original driver to get sound back.

I'll keep playing with it to see if I can get consistent performance. Once again, a big thanks to Ron and Mac for helping me through a very frustrating process.

Terry

BIAB/RB 2018 PlusPak. Dell Inspiron23 running Win10, 12GB RAM, 2.5GHz i7, Presonus AudioBox USB interface.