I don't know whose idea it was, but Windows 95 added a screen that appeared when you shut down Windows.
|It's now safe to turn off
This message was added because people would shut down Windows and then not know what to do next.
I witnessed this first hand once.
I was on an airplane flight, and the person sitting next to me was trying to turn off a laptop computer, which was running Windows NT. After selecting "Shut down", the operating system shut itself down, and then it displayed a screen that looked like this:
My seatmate saw this screen and clicked the Restart button.
Of course, this restarted the computer, and Windows started up again.
My seatmate, somewhat confused as to why the computer didn't shut down, selected "Shut down" a second time.
Again, the screen appeared:
And my seatmate performed the only option available: Restart.
At this point, I took the liberty of informing my seatmate, "You can just turn it off when you get to the moon-and-stars dialog."
"No, I can't do that. I was told I have to use the Shut Down menu to shut down. But the computer won't shut down!"
I had to explain, "This particular laptop doesn't know how to turn itself off. You have to turn it off manually via the power switch. Just wait for the moon-and-stars dialog to appear, and then you can push the power switch."
I'm guessing that the person on the plane next to me normally used a laptop that supported power management, and it was able to turn itself off via software. But the laptop that was brought onto the plane did not support power management, and it had to be turned off manually. And back in the day, most computers fell into the second category. Power management was one of those newfangled thingies that only the fancy-pants computers supported.
Enter the It's now safe to turn off your computer screen.
This message was displayed when shutdown was complete and the computer did not support software-initiated power-off. It told the user, "Okay, shutdown is complete. It's okay. You can hit the power button now. I won't get mad; I promise."