Second screen is not recognized - you can do that
If you connect two screens to your computer, a second screen is not always recognized immediately. The cause can be a defective cable or an incorrect setting in the system. We'll show you how to check why your second screen isn't being recognized.
Second screen is not recognized: Check the cable defect
First, check whether the cable with which you connected your monitor to the computer is defective.
- Connect your monitor and your computer with a different cable if you have a second monitor cable.
- If the screen works now, the other cable may be defective.
- If the screen still does not work, the problem is probably due to the video input on your computer or an incorrect system setting.
Computer does not recognize 2nd screen: 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 out all the 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 monitor via VGA, you may find another VGA connection on your computer. Connect the cable to the alternate connector and see if the screen is recognized.
- If you now see a picture, your onboard graphics card may be deactivated, which is why you can only bring a picture to the monitor via the additional graphics card.
- In the photo you can see such a case: the right connections are those of the graphics card (marked in red), while the left connections go to the mainboard. Since the onboard graphics card is deactivated by default, you can only get a picture with such a device via graphics card connections.
Activate the unrecognized screen in the system settings
Another option is that you have disconnected the monitor from your computer in the system settings. Follow these steps to reconnect a separate monitor:
- Right click on the desktop and select "Screen Resolution".
- If your computer receives a signal from the screen, you will see it on the display (see screenshot).
- Click on the separate monitor and select the menu item "Extend this display".
If you have connected your monitors via VGA, you could improve the display quality if you choose a different connection. We show you the differences between VGA and DVI.