I can't choose a port (Windows 10)

The option list is locked, appears in gray, I've used the arduino IDE for the windows store, I've downloaded the software from the oficial page and I've used Arduino create. All of them have the ports list locked.
Any ideas?

You probably have to install the driver for your Arduino. The Arduino IDE includes some drivers in the drivers folder of the Arduino IDE installation folder. Those only support official Arduino boards and clones that use the same USB-serial chip. If your clone uses a different USB-serial chip (most commonly CH340) then you need to download and install the driver. The fact that you didn't have a problem with the other IDE versions makes me think you may have a board supported by the standard drivers though as they would probably also have required you to download and install the driver for non-standard USB-serial chips.

For CREATE issues you may need to relax "driver enforcement" and have some "administrator" privileges.
That depends slightly on how your computer was set up.

You can google those two terms and there are plenty of results to help you.

Another aspect for CREATE can be the network connection type. Educational networks are usually a lot more strict so can block CREATE in which case you would need to get your network admin to allow the create process through.

Antivirus and other similar software can also cause issues with create and you might need to EXCLUDE the process from your AV etc.

Finally you have to remember that the browser you install the certificate for is the one you should use for create. So you cannot install the certificate for Firefox and expect it to work with Chrome unless you also install the certificate again for other browsers. Also be especially aware that some browser add ons can also block or stall the CREATE bridge process.

If you have any error logs or issues with the insall for CREATE do post them here so we can help you through the setup a little more.

EDIT BTW some of those items above may also pertain to the desktop IDE too.

Hi! Sorry for my english.
But I ve read that since January 2018 there is a new bootloader for Arduino nano.
On the Arduino IDE you have to select the

tools\BOARD TYPE\Arduino Nano then
tools\proccessor\ATmega328P (Old bootloader) then
tools\port\COMX (where X is the port number)

For boards manufactured before January 2018 you have to use the OLD bootloader
for boards after JANUARY 2018 you have to use the normal bootloader.

For more details read at

That all are ONLY for arduino NANO.

Hope that helps.

mourgos:
But I ve read that since January 2018 there is a new bootloader for Arduino nano.
On the Arduino IDE you have to select the

You're correct about this but the Tools > Processor selection has nothing to do with a port not appearing for the Arduino board. The problem you're referring to is related to the upload failing.