Well ver 4.2.2 resulted in the exact same message. " libusb_failed to load err -99 "
Wondering if I may have installed the wrong driver first.
Does reinstalling the driver completely over write the first attempt ?
This has stumped 2 other IT guys.  lol

Well that could be the problem in a nut shell. I unpacked V 3.12.3- windows.
I will punctually get 4.2.2 and post the results.
Thanks

Hi all.
Just got an antminer U2. for trial but cant get it to run. I keep getting  " err-99 libusb failed to start "
Running win 7  64 bit, installed driver using zadig , WinUSB v6.1.7600.16385 .
Tried driver updates, running in and out of admin, restarting and or repluging after , even get this message with just Cgminer exe , no u2 , no command line.
Got me frizzed.
Any help would be good !