How to connect a second monitor or TV in Windows and extend your screen

Steps

1. Pick the right cable and connect the displayCheck the video ports on your computer and on the monitor or TV: they may be HDMI, DisplayPort, Mini DisplayPort or USB-C. If both ends have the same port, use a straight cable; if they differ, get an adapter such as USB-C to HDMI or USB-C to DisplayPort. Not every USB-C port carries video; if you're not sure, check your computer's manual. Plug the cable firmly into the display first, then into the computer, and use the shortest cable you can.
2. Turn on the display and choose the right inputTurn on the monitor or TV. Use the Source (Input) button on the remote or on the monitor to select the port you plugged the cable into; for example, if you used HDMI 2, select HDMI 2. If the display is on the wrong input, you won't get a picture even when the computer is connected correctly.
3. Choose a display mode with Windows logo key + PPress the Windows logo key + P and pick what you want to see from the list. "PC screen only" keeps the picture on one display. "Duplicate" shows the same picture on both displays, which suits presentations or watching a film on the TV. "Extend" spreads your desktop across both displays so you can move windows from one to the other. "Second screen only" sends the picture only to the monitor or TV, and the laptop's own screen goes dark.
4. If the display doesn't appear, select DetectSelect Start and open Settings → System → Display. If the display you connected isn't shown there, scroll down, expand "Multiple displays" and select "Detect". If it still doesn't appear, unplug the cable at both ends, plug it back in and check the display's input again. Also install updates from Settings → Windows Update → Check for updates; an up-to-date graphics driver often fixes display problems.
5. Identify the displays and arrange them like your deskIn Settings → System → Display, select "Identify"; each display briefly shows its number. Drag the display boxes at the top of the page to match how they actually sit on your desk; for example, if the monitor is to the left of your laptop, move box 2 to the left. When the layout is right, select "Apply". Move the mouse pointer across the displays to check that it crosses at the right edge.
6. Set your main displayWhile in "Extend" mode, select the box for the display you want as your main display at the top of Display settings. Then open the "Multiple displays" section and select the check box that makes the selected display your main display. This way you can use a desk monitor as your main display and the laptop's own screen as a secondary one.
7. Adjust scale and resolutionSelect the display you want to change from the boxes at the top, then scroll to the "Scale & layout" section. Choose the size of text and apps from the "Scale" list and the resolution from the "Display resolution" list; for both, it's usually best to pick the one marked "(Recommended)". At a resolution lower than recommended, text may look blurry and the picture may shrink or have black borders. If you'll use the monitor in portrait, change the direction in the "Display orientation" list and physically rotate the monitor too.
8. Project wirelessly to your TVIf your TV supports Miracast, you don't need a cable. Turn on the TV; if you're using a Miracast adapter, make sure it's plugged into the TV's HDMI port. On the computer, press the Windows logo key + K to open "Cast", select your TV or adapter from the list and follow any instructions on the screen. You can also do this from Settings → System → Display → "Multiple displays" → "Connect". Once connected, you can still change the display mode with the Windows logo key + P.
9. Move windows between displaysIn "Extend" mode, grab a window by its title bar and drag it to the other display. To move it with the keyboard, select the window and press the Windows logo key + Shift + Left arrow or Right arrow; the active window moves to the monitor on the left or right. If you want the taskbar on every display, right-click the taskbar, select "Taskbar settings", expand "Taskbar behaviors" and check "Show my taskbar on all displays".