I am using Windows 7 on a regular PC. I tried to install Ubuntu on a Raspberry Pi 2 Model B and it didn't work. I downloaded Win32DiskImager utility and ubuntu-16.04-preinstalled-server-armhf+raspi2, wrote on the SD card, and then I got the attached screen and I don't know how to continue.
The login prompt appears before the boot process is complete, so you ended up with a screen like this in which the boot messages continue after the Ubuntu Server login prompt:
Sometimes when this happens you can wait until the boot messages stop and you get a blinking cursor, and then just press Enter and get a fresh login prompt. If that doesn't work, try to login again from a new virtual console.
Open a virtual console (tty) by using the keyboard shortcut Ctrl+Alt+F3.
login:prompt type your username and press Enter.
Password:prompt type your user password and press Enter.
If you still can't login, run the command:
sudo reboot from the console, and maybe you will get a working login prompt the next time when the Raspberry Pi reboots.