Arduino Nano 33 IoT cannot be found after Installing Arduino SAMD Boards

I'm new with Arduino Nano 33 IoT. So, I wanted to follow the instruction in
https://www.arduino.cc/en/Guide/NANO33IoT to get started.

First, I install the Arduino SAMD Boards, then I plugged in the Arduino to my PC and is recognized directly.
But then, I still cannot find the option to choose this newly installed board on the board list and Arduino is still suggesting me to Install a new package that I've just installed.

What did I do wrong? what should I do?

See the small RIGHT ARROW in your second pic ?
Also which version of the IDE are you using ?

Could you take a few moments to READ THIS.
It will help you get the best out of the forum.

What do you see when you click that ?

Bob.

Hi. I'm going to ask you to post the verbose compilation output from compiling for the Zero. I think this might provide us with some clues as to what is going wrong.

Please do this:

  • Tools > Board > Arduino/Genuino Zero (Programming Port)[/b]
  • (In the Arduino IDE) click File > Preferences
  • Check the box next to "Show verbose output during: > compilation
  • Click "OK"
  • Sketch > Verify/Compile
  • After the compilation fails you'll see a button on the right side of the orange bar "Copy error messages". Click that button.
  • In a forum reply here, click on the reply field.
  • Click the </> button on the forum toolbar. This will add the forum's code tags markup to your reply.
  • Press "Ctrl + V". This will paste the compilation output between the code tags.
  • Move the cursor outside of the code tags before you add any additional text to your reply.

If the length of the output exceeds the forum's 9000 character limit, save it in a .txt file and post it here as an attachment. If you click the "Reply" button you'll see the "Attachments and other options" link.