Nano-USB-Drivers
USB Interface Drivers: Arduino/YourDuino Nano
Most Nano boards use FTDI chips for USB interface. This uses the same FTDI drivers supplied with Arduino IDE. See it here:
However some use the WCH type CH340G chip and require a different driver. They are usually lower cost.
If you have this type of Nano, the USB chip on the underside of the board will be long and narrow, and marked WCH CH340G. See it HERE:
You need to install a different USB driver for these. Use the following procedure:
Download the driver software HERE:
(Your system may not allow downloading .EXE files, so click on this ZIP version):
You need Winzip or other utility to extract the EXE from the ZIP.
Before connecting the Nano to your USB port: Open “ch341ser.exe” file and run it.The software extracts about 8 files.
The software asks whether it can install the CH341SER.INF driver for the CH340 chip (Version 11/04/2011, 3.3.2011.11).
Click INSTALL
A Windows message asks whether the driver has installed correctly. Click YES.
Connect your Nano.
From Control Panel, open Device Manager and Ports. If installed correctly you should see an entry “USB-SERIAL CH340 (COMXX)
In the Arduino IDE, go to: Tools>Board (Select Nano) Tools>Port (Select the com port number found in Device Manager)<
Test by uploading File>Examples>Basics>Blink MAC Version: As always, It's Complicated. See the site HERE: