Hi.
I have not used a USS, I have an ESS. The ESS does not need a driver, the PC provides a driver for its Ethernet port but it does require a specialized driver for a USS.
Ergo the Windows USS driver. It needs to be downloaded, extracted and run/installed on your PC in order for the USS to communicate with the PC. You must go to
the Warp9 website and follow the instructions for installing the Windows USB driver.
In addition you need a plugin, its a program provided by Warp9 for their device, it is a go between the Mach3 application and the USS. It will need to be installed
in Mach3's plugin folder and then when Mach starts be selected as the active motion control plugin.
Start Mach go to Functions Cfgs\Reset Device Sel.... You will have to close Mach and then re-start. Mach should ask you which motion control plugin you wish to use,
select the one for the USS. You can dismiss the window and commonly you would check the box not to offer it again, once you've set the motion control plugin you don't
need to set it at each Mach start.
Craig