I'm making progress here. Do I need two separate copies of BFGMiner on the hard drive to run 2 instances? What happens to config file if I run 2 instances from one copy?
You definitely need 2 separate copies in different folders.
In my case, I only use one copy since I don't run the instances off of a config file. I just input the parameters as a shortcut target of bfgminer.exe (i.e. one shortcut with BE options and another with BFL options...and so on and so forth).