How to use a Laptop as a Second Monitor in Windows 11

Quick Summary: How to Use a Windows 11 Laptop as a Second Monitor

1. On the second laptop, open Settings > System > Projecting to this PC.
2. Click Optional features, search for Wireless Display, and install it.
3. Return to Projecting to this PC and set the top dropdown to Available everywhere on secure networks.
4. On your main PC, press Windows Key + K, select the second laptop name, and check the box to allow keyboard and mouse input.
5. Press Windows Key + P on your main PC and select Extend to stretch your desktop.

Method 1: Native Windows 11 Wireless Display (Free and Built In)

Microsoft includes a native screen-casting tool called Miracast inside modern editions of Windows 11. It allows one computer to beam its visual output directly over local Wi-Fi frequencies to another machine, creating a virtual second screen without third-party downloads.

Pre-Flight Check: Verify Miracast Support

Before configuring menus, check whether your wireless network cards support Miracast casting. On both your main PC and the second laptop, press Windows Key + R, type cmd, and press Enter. Inside the black command prompt terminal, paste this line and press Enter:

netsh wlan show drivers

Scroll down to the bottom lines of the output text and look for Wireless Display Supported. If it displays Yes (Graphics Driver: Yes, Wi-Fi Driver: Yes), your hardware is fully compatible. If it displays No, your wireless chip or graphics driver lacks screen-casting support, meaning you should skip to Method 2 or Method 3 below. To understand how modern mobile processors handle local display encoding, read our breakdown of Asus laptop display engineering.

Step 1: Configure the Second Laptop (The Receiver)

Pick up the spare notebook that will act as your monitor. In modern Windows 11 updates, the receiving tool is an optional system package that must be activated manually:

1. Open Settings by pressing Windows Key + I.
2. Navigate to System > Projecting to this PC.
3. If the setting options are grayed out, look for the link labeled Optional features near the top of the window. Click it, select View features (or Add an optional feature), type Wireless Display into the search box, check the box, and click Next > Install. Wait two minutes for the installation bar to finish.
4. Once installed, click the back arrow to return to the Projecting to this PC panel.
5. Set the top dropdown menu to Available everywhere on secure networks.
6. Set the second dropdown, Ask to project to this PC, to First time only.
7. Set Require PIN for pairing to First time. This presents a numeric security code on the screen during initial pairing to prevent outside neighbors from projecting to your laptop by mistake.
8. Click the blue text link labeled Launch the Wireless Display app to project to this PC. A blue window will open stating that your machine is ready for wireless connections. Keep this window open.

Step 2: Connect From Your Main PC (The Sender)

Move back to your main computer where you do your daily work. Connecting your display takes five seconds:

1. Press the shortcut keys Windows Key + K on your keyboard to open the Cast panel in the lower-right corner of your monitor.
2. Your main PC will scan nearby wireless airwaves. When the name of your second laptop appears in the list, click it.
3. Look at the screen of your second laptop. A six-digit or eight-digit PIN will appear. Type that number into the prompt box on your main PC and confirm.
4. Check the box labeled Allow mouse, keyboard, touch, and pen input from this device. This allows you to use the second laptop keyboard or trackpad to interact with windows resting on that screen.
5. Press Windows Key + P on your main computer to open the projection mode menu. Select Extend. Your desktop will stretch across both laptop panels.

You can now drag application windows, browser folders, and media players off the edge of your main screen straight onto your companion laptop display. Operating system interface polishes and display management match software updates we evaluated when Microsoft updated Windows 11 system components.

Method 2: The Zero-Lag Hardware Workaround ($12 USB Capture Card)

While native Miracast works well for general word processing, wireless connections introduce noticeable input lag. If you move your mouse cursor rapidly, you will spot a slight trailing pause. On crowded apartment Wi-Fi networks, the display stream can occasionally stutter or drop frames. If your work involves watching video feeds, editing timelines, or working on restricted corporate networks, a physical wired connection is superior.

Because your laptop lacks an HDMI-In port, you can add one for twelve dollars using a generic USB 3.0 to HDMI Video Capture Card (often sold online as an HDMI Cam Link style adapter). These tiny metal thumb drives take an incoming HDMI video feed, encode the visual data in hardware, and send it into your laptop as a standard USB webcam signal.

Step-by-Step Wired Setup

1. Plug an HDMI cable into the HDMI-Out port of your main work computer.
2. Plug the other end of that HDMI cable into the input port of the USB capture card.
3. Insert the USB capture card into an available USB 3.0 port on your second laptop. Windows will detect the device automatically as a USB Video Device without requiring manual driver installations.
4. On your main computer, press Windows Key + P and verify your display mode is set to Extend. Your main PC now treats the capture card as a standard 1080p desktop monitor.
5. On your second laptop, open the pre-installed Windows 11 Camera application.
6. Click the camera-flip icon in the top corner of the app to switch inputs from your integrated webcam to the USB Capture Card.
7. Press F11 (or click the fullscreen icon) to expand the Camera app window to fill the entire monitor.

Your second laptop now shows a clean, direct visual feed of your extended desktop with almost zero input lag. Because the visual stream travels through a physical wire, the setup works anywhere, including university libraries, hotel rooms, and client offices where public Wi-Fi networks block peer-to-peer device communication. If you manage multiple desktop accessories and external monitors, check our review of the Anker 12-in-1 desktop docking station to route high-resolution video streams through a single computer port.

Method 3: Third-Party Network Software (Spacedesk)

If your second laptop is an older machine running an outdated Windows build that rejects Miracast, or if you want to connect using an Ethernet cable rather than Wi-Fi, third-party software solves the problem. The most reliable free program for this purpose is Spacedesk.

Spacedesk installs a virtual display driver onto your main PC, converting your desktop workspace into an encrypted network stream that can be viewed on another computer, an Android tablet, or an iPad running the Spacedesk Viewer application.

Configuring Spacedesk

1. Go to spacedesk.net on your main PC and download the Spacedesk Driver (Server) for Windows 11. Run the installer and restart your computer when prompted.
2. On your second laptop, download and install the Spacedesk Viewer application.
3. Ensure both computers are connected to the exact same Wi-Fi network, or connect both machines together using a standard Ethernet cable.
4. Launch the Spacedesk Viewer app on your second laptop. The software will scan your local network and display the IP address and machine name of your main PC.
5. Click the connection link. Your main computer will recognize the second machine as an attached display monitor, extending your desktop automatically.

For users who do not want an extended desktop but simply want to control two separate computers with a single physical mouse and keyboard, explore Mouse Without Borders, a free tool included inside Microsoft PowerToys. It lets your mouse glide off the edge of one laptop screen directly onto an adjacent computer, copying text clipboards and files across both machines without streaming video pixels over the network. Hardware versatility and lightweight computing platforms match topics we analyzed when reviewing the Dell 14s portable laptop.

Performance and Quality Adjustments: Fixing Blurry Text and Stutter

Once your second screen is running, taking a few minutes to tune your display settings ensures text looks sharp and mouse movement feels natural.

1. Align Display Placement and Screen Heights

If you move your mouse to the right edge of your main laptop and the pointer bumps into an invisible wall, your virtual display positions do not match where your computers sit on your desk. On your main PC, open Settings > System > Display. Near the top of the menu, you will see two numbered boxes representing your monitors. Click and drag Monitor 2 so its position matches the physical placement of your second notebook on your desk (left, right, or slightly raised on a laptop stand). Click Apply. Your mouse will now glide across both screens in an unbroken line.

2. Match DPI Scaling to Eliminate Blurry Windows

Laptops feature different screen resolutions and physical panel sizes. If you drag a browser window from a sharp 14-inch 1400p panel to an older 15-inch 1080p laptop, text can look fuzzy or uncomfortably large. Under Settings > System > Display, click on Monitor 2. Scroll down to Scale & layout. If the dropdown is set to 150%, change it to 100% or 125% until interface icons and font text match the proportions of your main screen. Display sharpness and resolution scaling match principles we examined in our analysis of portable notebook display engineering.

3. Stop the Second Laptop From Hijacking Your Sound

When Windows connects to a wireless display or USB capture card, it often assumes you want audio to play through the new device. You may suddenly discover that Spotify music or video meeting voices are playing through the tiny, quiet speakers of your second laptop rather than your desktop speakers or headphones. To fix this, click the speaker icon in your main PC taskbar, click the Select a sound output icon beside the volume slider, and switch your audio output back to your primary headphones or studio speakers. Audio routing and acoustic balance match issues we explored in our review of the Sennheiser Momentum 5 wireless headphones.

4. Force 5 GHz Wi-Fi Bands to Prevent Stutter

If you use native Miracast, streaming video performance depends on clean radio waves. If both laptops sit on a crowded 2.4 GHz home Wi-Fi network, household microwave ovens, Bluetooth accessories, and neighboring routers will cause the display feed to stutter. Open your Wi-Fi settings on both machines and connect to your router 5 GHz network band. If you are traveling and have no external router, turn on Mobile Hotspot on your main PC (under Settings > Network & internet > Mobile hotspot), select the 5 GHz band, and connect your second laptop directly to your main PC hotspot. This creates a direct, high-speed local radio link that avoids outside network congestion.

Troubleshooting: Fixing the 4 Most Common Setup Errors

If your dual-monitor setup encounters a snag, consult this troubleshooting matrix to fix the underlying system issue quickly: