It troubled me for 4 days, I couldn't make it work even though the USB CH340 drivers were installed on my system and the Arduino Nano wasn't working (the Arduino Uno was working fine). I tried burning the bootloader and changing the processor from ATmega328P to ATmega328P (Old Bootloader), but nothing worked. Before throwing it out the window, I decided to download the drivers from the Arduino website, specifically the "CH340 driver for Windows 10". Miraculously, it worked perfectly with the ATmega328P processor