Fix: Second Monitor Not Detected

For better user experience and better productivity, users are using two or more monitors. This does not mean that you need to buy another computer or notebook and use two monitors. If your graphic card supports more output ports, you can connect more monitors. Based on that, a number of monitors you can connect to your computer or notebook depend on the number of output ports on your graphic card. What are output ports? Output ports provide a connection between computer or notebook and monitors. You can find different ports on your graphic card including VGA, DVI, HDMI and Display port. These days HDMI and Display ports are much more popular than VGA and DVI because VGA and DVI are old standards. HDMI is preferred because supports the bigger resolutions and provide transfer of audio signal. There are two different graphic cards, IGP (Integrated Graphic Processor) and PCIe graphic card. So, what is the difference between them? IGP is integrated into the motherboard, and PCIe is an external graphic card which can be installed in PCIe slot on your motherboard. If you are playing games, doing graphic design or video editing, we are recommending you to purchase an external graphic card with memory which is required by your applications.

Sometimes you will need to connect the second monitor to your machine. The procedure is really simple, you need to plug your cables to graphic card and monitor and enjoy working on your machine. Sometimes, it is not working well, because the second monitor is not detected by your machine. So what is the reason? There are different reasons including faulty cables, non-compatible drivers, and configuration issues.

This issue occurs on different operating systems, different computers and notebooks and different monitors. We will show you how to fix the issue on operating systems from Windows 7 to Windows 10.

If you want to use the second monitor, but you do not know where to start, please check instructions -> How to Setup Dual Monitors.

We created 13 methods which will help you to solve the issue with your monitors.

Method 1: Change projection mode

If you properly connected your monitors to your graphic card, and you do not see anything on your second monitor, you will need to change projection mode, because your graphic card does not know what to do with the second monitor. We will show you how to change projection mode on Windows 10. This procedure is compatible with Windows 8 and Windows 8.1, too.

1. Hold Windows logo and press P to open Projection mode
2. Choose proper projection mode between four options

For Windows Vista and Windows 7, read instructions on this dual monitor setup.

Method 2: Restart your computer

If the first method did not solve your problem, we are recommending you to restart your machine. After that. After that hold Windows logo and press P to choose proper project mode (Windows 8, Windows 8.1 and Windows 10).

Method 3: Turn off computer, monitors, and cables

Let’s try the third step which helped users to solve their issue with the second monitor. In this method, you will need to turn off all devices and wait few minutes, and after that, you will need to turn on your devices again. Please check procedure below.

1. Shutdown your computer or laptop
2. Shutdown your monitors
3. Unplug all power cables from computers, notebooks, and monitors
4. Unplug all cables between computers, notebook or monitors
5. Wait few minutes
6. Plug all cables back in
7. Turn on your computer or notebook and monitors

Method 4: Re-enable display adapters

Let’s try to do some software configuration. In this method, we will show you how to re-enable display adapter. Few users solved their problem by using this method. At first, you will need to disable your display adapter, and after that enable display adapter.

1. Hold Windows logo and press R
2. Type devmgmt.msc and press Enter
3. Navigate to Display adapter and choose your graphic card
4. Right click on graphic card and select Disable
5. Right click on graphic card and select Enable
6. Test your monitors
7. Restart your machine
8. Project your screen on second monitor (please check method 1)

Method 5: Reinstall monitors

In this method, you will reinstall your monitors. We will show you how to do it using Windows 10 and monitor Samsung S24D59L.

1. Hold Windows logo and press R
2. Type devmgmt.msc and press Enter
3. Navigate to Monitors and choose your monitor
4. Right click on your monitor and choose Uninstall
5. Click Uninstall to confirm uninstalling monitor
6. Restart your computer
7. Project your screen on second monitor (please check method 1)

Method 6: Rollback your drivers to the previous version

Did you update the driver for your graphic card and after that your machine is not detecting the second monitor? If yes, you will need to rollback driver of your graphic card. How will you do that? Please check instructions at this rollback drivers.

Method 7: Update graphic card driver

If you did not update your graphic driver, we are recommending you to update your driver with the latest driver version. You can do it using two ways. One is to update graphic card driver from Microsoft Update or you can download the official driver from vendor’s site. How will you do that? I wrote articles where I described the procedure of updating graphic card driver, which you can read on this video_tdr_failure nvlddmkm.sys, method 2. Based on that method, you will be able to find the proper driver for your graphic card.

Method 8: Change refresh rate

In this method, we will change monitor refresh rate. We will show you how to change frequency on Windows 10 using monitor Samsung S24D590L.

1. Hold Windows logo and press I to open Settings
2. Choose System
3. Click Display adapter properties at the bottom of the window
4. Choose Monitor tab
5. Under Screen refresh rate choose 60 Hertz. If it was already 60 Hertz, select something else and then select “60 Hertz”.
6. Click Apply and then OK
7. Project your screen on second monitor (please check method 1)

Method 9: Try some tricks

If you are using a notebook, we are recommending you to try some tricks.

1. Try to close the notebook lid while connected to your monitor (this means the laptop display will be temporarily disabled). The monitor will be now seen as the main display and once you open the lid you’ll have both displays working, a trick simple as that.
2. Try putting the computer to sleep while connected to monitor via HDMI and wake it up. That also worked for few users.

Method 10: Turn on Multiple Display

If you installed the full driver for your NVIDIA and AMD graphic cards, you will need to run NVIDIA or AMD software to enable Multiple Display. We will show you how to turn on multiple displays using NVIDIA Control Panel.

1. Click Start menu and type NVIDIA Control Panel
2. Open NVIDIA Control Panel
3. Choose Display
4. Click Set up multiple displays
5. Select displays you want to use
6. Click Save
7. Restart your Windows

Method 11: Update your BIOS

If you are using motherboard which supports integrated graphic cards with two ports, we are recommending you to update your BIOS of UEFI. We talk about updating BIOS or UEFI many times. To do an update of your BIOS or UEFI we are recommending you to check this https://appuals.com/fix-video_tdr_failure-nvlddmkm-sys/, method 15, where I described the procedure of updating BIOS on Asus motherboard.

Method 12: Revert your operating system to the previous version

If you are one of the users who updated machine from Windows 7, Windows 8 or Windows 8.1 to Windows 10, and after that, you can not use the second monitor, we are recommending you to revert your Windows to the previous version where everything worked properly. Why? Because your graphic card or graphic card driver is not properly compatible with Windows 10. You will need to wait for a proper update for your graphic card. Please do not use fix from third party websites.

Method 13: Check monitor, splitters, and cables

First, three methods did not solve your problem and you are waiting for best solutions. We are doing this step by step, so please be patient. In this method, you will test your monitor and cables which provide a connection between your computer or notebook and monitors. As we said at the beginning of this article, you can use VGA, DVI, HDMI and Display port. Let’s start with the testing monitor. If the first monitor is working without any problems, unplug the first monitor from computer or notebook and connect the second monitor to the same cable. But, if the second monitor does not support the same cable? In that case, use another cable and check the second monitor. If your monitor is not working on two different ports and two different ports, you will need to purchase another one monitor.

If the second monitor is working on the first cable and not on the second cable, please change the cable. Also, if you are using VGA, DVI or HDMI splitter and there is an issue with splitter, you will need to change it by a new one.