PC Doesn't recognize second monitor

Hello，GioQI

Thank you for posting in the Microsoft community.

Regarding the issue of your computer not recognizing a second monitor, there are many factors that can lead to this problem, such as cable, monitor, interface, or graphics card driver issues. It is recommended that you can start by doing some cross-testing to help determine if the problem is with the monitor itself or the cable.

First, you can follow the steps below to check the cable itself:

• Try connecting the cable from the first monitor to the second monitor and check if the second monitor is able to display content properly.

• If the second monitor works properly, then the problem may be with the cable or connection method.

  If the second monitor still does not work, then there may be a problem with the monitor itself.

Next, test the monitor itself:

• If it's convenient, you can connect this monitor to another computer device using the same cable and check if it works properly.

At the same time, in order to exclude the influence of the resolution, it is recommended to turn down the resolution of the two monitors and set them to the same resolution for testing, which will be able to test more accurately.

Looking forward to the information you provide to better determine the cause of the problem. Thank you for your understanding and cooperation!

Best Regards，

Rota|Microsoft Community Support Specialist

Both monitors work on separate devices, already switched around cables