Key Takeaways
- Physically unplug the second monitor's cable from your computer or docking station — the operating system will detect the change within seconds.
- Windows and Mac automatically switch to single-monitor mode, but you can manually adjust display settings if windows don't reposition correctly.
- Any windows or programs that were open on the second monitor will move to your primary display, though they may appear off-screen until you reposition them.
- If you plan to use two monitors again later, your computer remembers your previous two-monitor setup and restores it when you reconnect.
Disconnect the Second Monitor's Cable
The first step is to unplug the cable connecting your second monitor to your computer. This cable is usually DisplayPort, HDMI, or USB-C, depending on your monitor and computer model. If your second monitor connects through a docking station rather than directly to your computer, unplug the cable from the docking station instead.
Your operating system will recognize the disconnection within a few seconds. You do not need to shut down your computer or restart anything — the change happens while you are working. If you are using a laptop with an external monitor, closing the laptop lid will also trigger single-monitor mode, though the laptop screen becomes your only display in that case.
Windows: Check Display Settings After Disconnection
On Windows, open Settings by pressing the Windows key and typing "display settings," then press Enter. The Display page will show only one monitor listed now. Windows automatically makes your primary monitor (usually the one on the left in the display diagram) your active display, and any windows that were on the second monitor shift to the primary one.
If windows appear cut off or positioned incorrectly after the switch, you can manually move them. Click and drag the title bar of any window to reposition it on your single screen. If a window is completely off-screen and you cannot see its title bar, right-click the program in the taskbar, select "Move," then use your arrow keys to drag it back into view.
You can also check the "Scale and layout" section on the same Display Settings page to confirm your resolution is set correctly for your single monitor. Most monitors work best at their native resolution, which Windows usually sets automatically.
Mac: Adjust Display Preferences if Needed
On a Mac, go to System Settings (or System Preferences on older versions), then click "Displays." Your Mac will show only one display now. If windows from your second monitor do not automatically reposition, you can manually move them by clicking and dragging their title bars to your remaining screen.
If you had set up different brightness or color settings for each monitor, those settings are stored separately. Your Mac remembers them and will restore them if you reconnect the second monitor later. You do not need to adjust anything unless your single monitor's brightness or colors look wrong to you.
What Happens to Open Windows and Programs
When you disconnect the second monitor, any windows that were open on that screen automatically move to your primary display. Programs continue running — nothing closes or stops working. However, if you had many windows spread across both monitors, they may stack on top of each other on your single screen, making it hard to find what you need.
The easiest way to organize them is to use Alt+Tab (Windows) or Command+Tab (Mac) to cycle through open windows and move each one to a clear area of your screen. Alternatively, you can minimize windows you are not using right now and open them again later when you have more space. If you regularly switch between one and two monitors, consider saving your window positions — both Windows and Mac have built-in tools to remember layouts, though they require a bit of setup.
Reconnecting Two Monitors Later
If you plug the second monitor back in, your computer will recognize it and restore your previous two-monitor setup automatically. Windows and Mac both remember which monitor was primary, which was secondary, and where you had positioned your windows. You may need to wait a few seconds for the system to detect the reconnected monitor, but you should not have to adjust settings manually.
If the second monitor does not appear after you plug it in, try unplugging and replugging the cable, or restart your computer. Occasionally a cable connection becomes loose or a driver needs to refresh, but reconnection usually works when ready.
Troubleshooting Common Issues
If your single monitor goes black after disconnecting the second one, your computer may have switched to an output that no longer exists. Restart your computer — it will boot up using your remaining monitor. If the screen stays black, try pressing Windows+P (on Windows) or using Mission Control (on Mac) to manually select your display, though this is rare.
If windows are stuck off-screen and you cannot move them back, the quickest fix is to restart the program. Close it completely and open it again — it will appear on your primary monitor. For persistent problems, you can reset your display settings to default by going back to Display Settings and choosing "Reset" or "Restore defaults," though this will also reset any custom resolution or scaling you had configured.
Frequently Asked Questions
Do I need to restart my computer to switch to one monitor?
No. straightforward unplugging the second monitor is enough — your operating system detects the change within seconds and adjusts automatically. Restarting is only necessary if something goes wrong, like your screen going black or a window getting stuck off-screen.
Will my programs close when I disconnect the second monitor?
No. All open programs and windows stay running. Windows that were on the second monitor move to your primary display, though they may overlap or appear in unexpected positions until you reposition them manually.
What if I want to keep my two-monitor setup but just use one monitor temporarily?
You can leave the second monitor plugged in but turn it off using its power button. Your computer will still detect it as connected, so windows may still try to use it. Fully unplugging the cable is cleaner if you want to truly switch to single-monitor mode.
Can I choose which monitor becomes my primary display?
Yes. In Windows Display Settings or Mac Displays preferences, you can drag the monitor diagram to change which one is primary. However, once you disconnect the second monitor, only one remains, so this setting does not explore until you reconnect.
Will my computer remember my settings if I switch between one and two monitors often?
Yes. Both Windows and Mac store your previous configuration and restore it when you reconnect. If you switch frequently, you may want to use a docking station with a single cable connection — unplugging one cable is faster than managing multiple monitor cables.