Hello there,
I am having the same problem, USB Serial Converter A and B are listed in the device manager, description is "Digilent USB Device" on both serial converters. But, in my case, the adept system does detect my board.
The same basys 3 board is being detected in other PCs. And taking other basys 3s that are actually working on other PCs are neither working on mine.
Thank you,
Manu