It could happen when you log back to your desktop after remotely logging into your desktop and logging off.
What happened to me was I logged into my office desktop from home and logged off. Then I came to work and when I logged in to my desktop with dual monitors, I saw the above message on the second monitor. Just shutting down the desktop and restarting worked!
what is the display resolution for a CGA monitor?
The "input not supported" message typically means that the monitor is receiving a signal that it cannot display, often due to a resolution or refresh rate mismatch. To fix this, try booting your computer in Safe Mode by pressing F8 during startup, then access the display settings by right-clicking on the desktop and selecting "Display settings." Set the resolution to a supported value for your Acer monitor, typically 1920x1080, and ensure the refresh rate is set to 60Hz. If that doesn't work, try connecting the monitor to a different computer to rule out hardware issues.
monitor is an output (display) device
monitor
LCD Monitor
Pictures on the display screen(monitor) are made up of
There is no difference. A LCD Monitor (Liquid Crystal Display) is a type of VDU (Visual Display Unit).
Another name for Visual Display Unit is a monitor. A monitor is an electronic device that displays images generated by a computer. It is also commonly referred to as a screen or display. The monitor allows users to visually interact with the information and data processed by the computer.
LCD monitor
Your monitor/display system.
A TFT monitor
A computer monitor is hardware. It only provides for display.