Ubuntu 20.04 not booting to desktop

I have not used Ubuntu for years, but the other day, trying to install Ubuntu 13.04 on a friend's computer, I had nightmares again: after an apparently successful installation the system "hangs" on startup and an az screen appears ... Sorry, Violet, after remembering Mark Shuttleworth and his entire family, I came up with the solution, which I share with you.

The error usually happens when using Nvidia or AMD video cards, or a laptop with Optimus or similar, which allows the use of 2 interchangeable graphics cards. Ubuntu, as it does not come with the proprietary drivers installed, may have problems working with them.

The solution is to boot Ubuntu, once in nomodeset mode to bypass the black or purple screen (as the case may be), download and install the appropriate drivers, and then reboot to fix the problem forever.

Steps to follow

1.- Start the computer and press the Shift key on startup, to get the Grub menu. Use the arrow keys to navigate / highlight the entry that corresponds to Ubuntu (usually the first one).

2.- Press the e key to edit the entry, which will display detailed boot information:

3.- Find the entry as shown in the screenshot above. Use the keyboard arrows to get to it, and then I pressed the End key to go to the end of the line (which can be on the next line, paradoxically).

I entered the word nomodeset as shown in the screenshot and hit Ctrl + X to start the system.

If all goes well, the system will boot without problems and you will be able to install the proprietary drivers.