command prompt in fastboot on my device lg k20

Is there any way to upgrade my lg k20 to a fast load usb 3.0 my pc has only 3.0 hubs, the windows troubleshooter is telling me to use 2.0 I have no bus or converter and the lg bridge supports the indicator mode of commands that I ask because my device is in fastbootmode on screen but my PC does not open the command prompt