Arduino port grayed out for Fake Board with CH340 I have downloaded and used Arduino IDE v1.8.4 from official site (needs no install) for windows10, and connected my random board with a ch340, but it's LED is only blinking and I can't select the port (ie. it's grayed). 

I did test all USB ports and restarted my laptop but that didn't work!  

I tried to install 1.6.9 IDE that I had before, but again the port option is unselectable!

This is my board: 
http://uupload.ir/files/xgv_uno.jpg
Simplest possible thing would be that you do not have CH340g driver installed and you should try installing it first; These boards use CH340 for usb to serial and they need the driver to be installed; Please give it a try by getting the driver from the following link http://www.wch.cn/download/CH341SER_EXE.html or any other reliable source if there is any problem with the link;

If the board is not recognized even after that, it could be a bad USB port or a bad USB cable or even a board with the CH340 chip dead;