BK Precision has discontinued the 866.
https://www.bkprecision.com/products/discontinued/866-universal-device-programmer-with-usb-interface.htmlThey still have a link to the software under "docs and software". Version V3.64.
Unfortunately, they discontinued support for the 866 in version 3.32 and so V3.64 won't work (and installing it will throw away your old working version unless you saved the old installer).
BK Precision are clueless and can only offer a far earlier version V2.39. They were however kind enough to tell me I could uprade to the 866C for $1145
I was able to download V3.32 for the (parent) Elnec product, and as long as I select "beeprog" it seems to work
but I'm wondering anyone happens to have a copy of the BK V3.32 installer saved anywhere.
Ignore. BK finally clued themselves in.
If anyone else ever needs the final 3.32 version for the 866 drop me a line [as of now they removed the bogus version, who knows if they'll add back in this correct one]