CH340 of Arduino MEGA 2560 R3 device driver download

If  you use cheap  Arduino MEGA 2560 R3 and unable to install driver encountered
如果您使用很便宜的 Arduino MEGA 2560 R3 ,又遇到無法安裝驅動程式,

Maybe it use cheap CH340  virtual serial port
也許使用了便宜的CH340 虛擬串口晶片