If you connect two screens to your computer, a second screen is not always recognized immediately. The cause can be a defective cable as well as an incorrect setting in the System. We show you how to check why your second screen is not recognized.
Windows 10 not detecting second monitor: check cable defect
First, check whether the cable you used to connect your Monitor to the computer is defective.
Connect your Monitor and computer to another cable if you have a second monitor cable.
If the screen works now, the other cable may be defective.
However, if the screen still does not work, the Problem is probably due to the video input of your computer or an incorrect system setting.
Windows 10 not detecting second monitor: Inactive or defective Video input
If your second Monitor has different connections, you should check whether you can connect it via HDMI instead of VGA, for example. Even if this is not the case, you can try the other inputs on your computer.
Many computers have multiple video inputs: VGA, DVI, HDMI and Displayport are the most common. Try all inputs for which you have the appropriate cables.
In addition, you will usually find several inputs of the same type on computers. For example, if you have connected your second screen via VGA, you may find another VGA port on your Computer. Connect the cable to the alternative port and check if the screen is detected.
If you now see an image, your onboard graphics card may be disabled, which is why you only bring an image to the Monitor via the additional graphics card.
On the photo you see such a case: the right connectors are those of the graphics card (marked in red), while the left connectors go to the motherboard. Since the Onboard graphics card is disabled by default, with such a device you only get an image via graphics card connectors.
Windows 10 not detecting second monitor: Enable unrecognized screen in System Settings
Another possibility is that you have disconnected the Monitor from your computer in the system settings. Follow these steps to reconnect a separate Monitor:
Right-click the Desktop and select “screen resolution”.
If your computer receives a Signal from the screen, you will see it in the display (see Screenshot).
Click on the separate Monitor and select the menu item “expand this display”.
If you have connected your screens via VGA, you could improve the display quality if you choose a different connection. We will show you the differences between VGA and DVI.