@kpax,
It seems you have an issue with the drivers on this one. Sometimes when you install Vivado the drivers don't install correctly. So, if you have vivado Installed, please try to install manually the drivers. Here is the path to file the cable drives, It's the same on each installer: C:\Xilinx\Vivado\2015.4\data\xicom\cable_drivers\nt64\digilent I have a previous version of Vivado, you'll have 2017.2
Please try this and if it's not working we'll see if there's anything else we can do
Best regards,
Bianca