Multi dollar question, real or fake Arduino. If it's from Ali, eBay or Amezon it's probably fake. The IDE only comes with drivers for the real Arduino's. If it's a fake, have a close look at the chip next to the USB port.And did you use the CH340 driver from the manufacturer?
Fake was the wrong word, clone. All Arduino's from China at least are clones so AliExpress, Banggood, eBay, Amazon etc all are 99% clones. Nothing wrong with clones, that's why it's open source (Although a contribution to Arduino is nice if you do buy clones, like me.)And what to look for on the chip? The real deal has a FT232 chip on it from FTDI. Although not 100% guarantee it's real if you do have that chip. Up until FTDI-gate that was a popular chip on clone Arduino's. Only problem, the clones DID use fake chips for that..So big piece of the puzzle, where did you buy it?
The device needs to show up in device manager whatsoever. Being it recognized (as COM), being it faulty (with a !) or just as unknown device. If it does not show up at all you have a different problem (because the PC doesn't even get as far as looking for the driver).Is the Arduino connected to a USB 3.x port? Some chips just doesn't seem to like those, try a USB 2.0 port.
That's the problem - it probably did show up somewhere in the device manager but the tedium of going through every device looking for the associated driver was too much. So I have reverted the machine to it's virgin state and I'll plug it in tonight when it should show up probably as an unidentified item then I can point it to the drivers. I have used different cables but it only has USB 2.0 ports - it dates from 2009.
Take a look here for the driver instructions and guide:https://www.google.co.uk/amp/www.instructables.com/id/Arduino-Nano-CH340/%3famp_page=true
Maybe unrelated but one of the boards is running hot and it's LEDs seem brighter. The input voltage is correct (12vdc) what could cause this?