Why can't I change the scale of the screen of the LCD with the [Fn]+[F] keys?

Why can't I change the scale of the screen of the LCD with the [Fn]+[F] keys during the operation of Windows or after system recovery?

Try setting the resolution of the screen to 800 x 600 or lesser and then change the scale of the LCD screen with the [Fn]+[F] keys.
The [Fn]+[F] keys work only in the following cases when Windows is running and they do not function when the resolution of the screen is set to 1024 x 768.

Refer to the procedure below when you want to switch the scale of the screen when the screen area is 800 x 600 or lesser:
* Procedure
1. Start Windows.
2. Click Start, click Settings, click Control Panel and double-click Display.
3. Click the Settings tab and move the slide bar to set the resolution of the screen to 800 x 600 or lesser.
4. Set the scale of the screen using the [Fn]+[F] keys.