I flashed TWRP in my phone and it didn't boot anymore. I didn't have any image of any operating system in my sdcard and my pc hasn't a sd card slot.
So I started thinking, I googled for some solution, I tried the official tools, but nothing worked. So I started writing an adb script able to download the image from the server and install it in my phone.
While I was doing it I was also explaining my troubles to my no-tech friend. She's not confident with computers, she's able only to turn the pc on and go to Facebook.
She told me "why don't you put your sd card in another phone and download the operating system from it?"

She literally saved my day.

Sometimes we are so busy with our geek things and we forget trivial solutions