It's not uncommon for people with desktops today to have multiple monitors set up, that is more than one monitor hooked up to one computer. When I first experimented with this back in the early Windows XP days, I had to put two video cards into my computer and go into the BIOS and set the default video to boot from.
Most modern day computers and video cards come with a number of plugins for multiple monitor setup. I've had a more permanent dual monitor setup since 2012 when I bought my Acer Windows 7 desktop.
So first you have to plug in all your monitors to your computer. If your monitor and computer plugins are not compatible, you can usually get some kind of adapter to make it work.
Once you have all your monitors hooked up, don't panic if one just shows a blank screen. I faced this issue more than once in the past. So on the screen that is visible, right click on the desktop.
In Windows 7 it's listed as Screen resolution in Windows 10 it's Display settings. Click on it.
You'll see in the right-hand side a graphic representing your monitor setup. You'll see more that two if you have more monitors. There are two buttons under that labelled Identify and Detect. Click on the Detect button first. Your second monitor should now be visible. Even if both monitors are visible, the detect button can sometimes help you with resolution issues.
Then there is an Identify button. This will flash a number on your monitors to help identify your setup. On Windows 10 it shows as black boxes in the corner identifying each monitor. On Windows 7 systems it flashes a large white number on the screen. I think I like the Windows 7 way better.
By this time everything might be working properly. If not scroll down slightly to the Multiple displays area. This setting should be on Extend these displays. This is the setting needed for all your monitors to act as one big one.
If this is set to Duplicate these displays, it will be like having one monitor but showing the same thing on both displays. Show only on 1 and Show only on 2. If you wanted to disable a monitor without actually unplugging it, you could choose one of these options.
If you want to extend the taskbar at the bottom of the screen onto your other displays, you have to go into your taskbar settings to do this. So right click on your taskbar
and click on Taskbar settings and scroll down to the Multiple display settings. Click on the switch under Show taskbar on all displays. There are a few other settings under that to experiment with. I just turned it on. Windows 7 and earlier don't give you this option.
Back to the display settings. If you go back to the top graphic, the highlighted one, in my case coloured purple, the settings you are seeing are for that monitor and one of them should be set to Make this my main monitor. My first monitor is already set to this, and the setting is unclickable. If I wanted to switch over I would go to the graphic click on the number two monitor icon, come down here to the Multiple display settings and check that option. The first one would automatically get unchecked.
If your monitors setup in the picture doesn't match up with your real life setup, you can just click on one and drag it in front of the other. If my main monitor was showing as number 2, I could just click down and drag it over to better represent my setup. Then you would have to click on Apply in the new setup, easier than moving your monitors around.
So that's some of the basics about setting up a dual monitor system. The layout may be slightly different but the options work basically the same in earlier versions of Windows.
