Hi there,
You may try , Openning the device manager and right click on Jtag or USb device ,then click update the driver. Note what is says it is, download seeed’s driver and , choose let me pick the driver file and navigate to the seeed driver and select that. reboot and try again,
Also ZADIG can be used to change the drivers may be easier.
HTH
GL 
PJ 
I plugged in a C3 and here is what this looks like.
