wemos D1 R2 not seen by windows device manager

I am trying to set up a mesh network using D1 R2 modules.

I am having problems with connecting the D1 R2 modules to the PC - the Device manager does not always recognize the devices. At first I could communicate with the first one that was plugged in but additional modules on different usb ports were not detected. Now even the first device is not detected.

Any sugestions ?

June 12th

Found problem to be due to faulty usb cables. However some good has come of it:- the link below has a good guide to removing hidden (unused) com port assignments.