A green screen that Barney will give you if you are mean to him, or he does something that he wasn't supposed to do, in which you get when the
computer crashes, thus you must manually restart your
computer, also if Barney does something and it was his fault you received a green screen of death, instead of the normal mad Barney pointing his arrow at the message telling you that you need to restart your
computer, he will point his arrow at the reason why it crashed, and he will be shocked, and there will be a note from Barney explaining to you what happened, and there will be an item or video thumbnail that cause the computer to crash with a
red prohibition sign on it, and he will tell you that you
may need to install something to prevent this from happening again, preferably a driver or antivirus, and may even restart your computer for you.