Having a second monitor can drastically improve productivity, whether you’re coding, editing videos, writing articles, or simply multitasking. But what if you don’t have a dedicated external monitor? The good news is, you can often repurpose an old (or even a newer) laptop as a secondary display. This guide will walk you through several methods to achieve this, covering both wired and wireless solutions, along with troubleshooting tips to ensure a smooth setup.
Understanding the Possibilities and Limitations
Before diving into the how-to, it’s crucial to understand what’s possible and what’s not. Not all laptops are created equal when it comes to using them as external displays. Ideally, you’d want a dedicated video input port, like HDMI-in, on the laptop you intend to use as the secondary screen. However, these are rare. Most laptops only have video output ports (HDMI-out, DisplayPort). This means you generally can’t directly connect one laptop to another and have it “just work” as a monitor.
Instead, we’ll rely on software solutions that leverage your network connection to stream the display from your primary laptop to the secondary one. These methods generally involve installing applications on both laptops and configuring them to communicate.
Method 1: Using Windows’ Built-in Projecting to This PC Feature
Windows offers a built-in feature called “Projecting to this PC” which allows you to use a Windows laptop as a wireless display. This feature is relatively simple to set up, making it a great option for users who want a quick and easy solution.
Preparing the Secondary Laptop (The “Receiver”)
First, you’ll need to enable the “Projecting to this PC” feature on the laptop you want to use as the secondary monitor.
- Open the Settings app on the secondary laptop. You can do this by pressing the Windows key + I.
- Navigate to System > Projecting to this PC.
- Under “Some Windows and Android devices can project to this PC when you say it’s OK,” select “Available everywhere” or “Available everywhere on secure networks” from the dropdown menu. The latter is generally recommended for security.
- Choose your preferred option for “Ask to project to this PC.” You can select “First time only” or “Every time a connection is required.” Choosing “First time only” is usually more convenient.
- If desired, set a PIN for pairing under “Require PIN for pairing.” This adds an extra layer of security.
- Note the “PC name” displayed at the bottom of the settings page. You’ll need this later.
It’s important to ensure that Wireless Display Optional Feature is installed. To check:
- Go to Settings > Apps > Optional features.
- If “Wireless Display” isn’t listed, click “Add a feature”.
- Search for “Wireless Display” and install it.
Connecting From the Primary Laptop (The “Projector”)
Now, you’ll connect from your primary laptop to the secondary laptop.
- On your primary laptop, press the Windows key + P. This will open the “Project” menu.
- Select “Connect to a wireless display”.
- Windows will search for available wireless displays. Select the name of your secondary laptop from the list.
- A connection request will appear on the secondary laptop. Approve the connection.
- Choose your preferred projection mode: Duplicate, Extend, Second screen only. “Extend” is usually the best option for using the second laptop as a true secondary monitor.
If you encounter issues, make sure both laptops are on the same Wi-Fi network and that the firewall isn’t blocking the connection.
Troubleshooting Windows Projecting Issues
Sometimes, the built-in Windows feature doesn’t work perfectly. Here are a few troubleshooting steps:
- Firewall: Ensure that Windows Firewall (or any other firewall software you’re using) isn’t blocking the connection. You may need to create an exception for the Wireless Display feature.
- Driver Issues: Outdated or incompatible graphics drivers can cause problems. Update your graphics drivers on both laptops.
- Network Issues: A weak or unstable Wi-Fi connection can lead to connection drops or performance issues. Try moving the laptops closer to the router or using a wired connection on at least one of the devices.
- Feature Conflicts: Some third-party screen sharing applications may conflict with the built-in Windows feature. Try disabling or uninstalling any other screen sharing software.
- Older Hardware: Older laptops, especially those with older Wi-Fi adapters, may struggle to maintain a stable connection.
Method 2: Using Third-Party Software Solutions
Several third-party applications are designed specifically for using one laptop as a second monitor. These apps often offer more features and better performance than the built-in Windows option. Some popular choices include Spacedesk, Duet Display, and MaxiVista.
Spacedesk: A Popular Free Option
Spacedesk is a free software solution that allows you to turn your Android tablet, phone, or even another Windows laptop into a secondary display. It’s a popular choice due to its cost-effectiveness and relatively easy setup.
Installing Spacedesk
- Download and Install the Spacedesk Driver: On the primary laptop (the one you want to extend the display from), download and install the Spacedesk driver software from the Spacedesk website. Make sure to download the correct version for your operating system (Windows 10/11). Reboot your primary laptop after installation.
- Download and Install the Spacedesk Viewer: On the secondary laptop (the one you want to use as the secondary monitor), download and install the Spacedesk viewer app from the Spacedesk website.
- Ensure both laptops are on the same network.
Configuring Spacedesk
- Launch the Spacedesk Driver Console: On the primary laptop, the Spacedesk driver should be running in the system tray. You can open the Spacedesk Driver Console by right-clicking the icon in the system tray and selecting “Spacedesk Driver Console”.
- Start the Spacedesk Viewer: On the secondary laptop, launch the Spacedesk viewer app. It will automatically scan for Spacedesk servers on the network.
- Connect to the Primary Laptop: The Spacedesk viewer app should display the name of your primary laptop. Click on it to connect.
- Configure Display Settings: Once connected, Windows should recognize the secondary laptop as a second monitor. You can configure the display settings (resolution, orientation, etc.) in the Windows Display Settings (Settings > System > Display).
Spacedesk Advantages and Disadvantages
Advantages:
- Free to use.
- Supports a variety of devices (Windows, Android).
- Relatively easy to set up.
Disadvantages:
- Performance can be affected by network conditions.
- May experience lag or latency, especially over Wi-Fi.
- Can be resource-intensive on older hardware.
Duet Display: A Paid, High-Performance Option
Duet Display is a paid application that offers a more polished and high-performance experience compared to free alternatives like Spacedesk. It’s designed to provide a seamless and lag-free experience, making it suitable for demanding tasks like video editing and gaming (though gaming on a secondary laptop screen is generally not recommended due to latency).
Installing Duet Display
- Purchase and Download Duet Display: Purchase and download the Duet Display application from the Duet Display website. They offer versions for Windows and macOS.
- Install Duet Display on Both Laptops: Install the Duet Display application on both the primary and secondary laptops.
- Create an Account/Log In: Launch the application and create an account or log in if you already have one.
Configuring Duet Display
- Connect the Laptops: Connect the two laptops using a USB cable. Duet Display recommends using a USB connection for the best performance. Wireless connections are also supported, but they may be less stable and have higher latency.
- Launch Duet Display: Launch the Duet Display application on both laptops.
- Configure Display Settings: Duet Display will automatically detect the secondary laptop as a second monitor. You can configure the display settings (resolution, frame rate, etc.) within the Duet Display application.
Duet Display Advantages and Disadvantages
Advantages:
- High performance and low latency, especially over USB.
- Seamless integration with Windows and macOS.
- Offers advanced features like touch input and Apple Pencil support (on iPads).
Disadvantages:
- It is a paid application.
- Requires installation on both laptops.
- Performance may vary depending on the hardware and connection type.
MaxiVista: A Feature-Rich Professional Solution
MaxiVista is another paid software solution that allows you to extend your desktop to another PC. It boasts features targeted towards professional use, such as support for multiple monitors and advanced configuration options.
Installing MaxiVista
- Purchase and Download MaxiVista: Purchase and download the MaxiVista software from their official website.
- Install MaxiVista on Both Laptops: Install the MaxiVista software on both the primary (server) and secondary (client) laptops.
- Obtain a License Key: Activate the software using the license key provided after purchase.
Configuring MaxiVista
- Run MaxiVista Server: On the primary laptop, launch the MaxiVista Server application.
- Run MaxiVista Client: On the secondary laptop, launch the MaxiVista Client application.
- Configure Connection: The client should automatically detect the server on the network. If not, you may need to manually specify the server’s IP address.
- Adjust Display Settings: Once connected, adjust the display settings in the MaxiVista Server application. You can configure the resolution, position, and orientation of the secondary display.
MaxiVista Advantages and Disadvantages
Advantages:
- Supports multiple secondary displays.
- Offers advanced configuration options.
- Suitable for professional use.
Disadvantages:
- It is a paid software solution.
- Can be more complex to set up compared to other options.
- May require a powerful network for optimal performance with multiple monitors.
Optimizing Performance and Addressing Latency
Regardless of the method you choose, latency can be a significant issue when using a laptop as a second monitor. Here are some tips to optimize performance and minimize latency:
- Use a Wired Connection: Whenever possible, use a wired Ethernet connection instead of Wi-Fi. A wired connection provides a more stable and faster connection, reducing latency and improving overall performance.
- Close Unnecessary Applications: Close any unnecessary applications on both laptops to free up system resources.
- Adjust Display Settings: Lowering the resolution and refresh rate of the secondary display can help reduce latency.
- Update Drivers: Ensure that your graphics drivers and network drivers are up to date.
- Optimize Network Settings: Check your router settings and ensure that Quality of Service (QoS) is enabled and prioritizing network traffic for the screen sharing application.
- Hardware Acceleration: Enable hardware acceleration in the screen sharing application if available.
- Monitor CPU and Memory Usage: Keep an eye on CPU and memory usage on both laptops. If either laptop is consistently running at high utilization, it may be a sign that the hardware is struggling to keep up.
Security Considerations
When using your laptop as a secondary display, it’s important to be aware of the security implications.
- Secure Network: Always use a secure Wi-Fi network with a strong password. Avoid using public Wi-Fi networks, as they are often unsecured and can be vulnerable to eavesdropping.
- Firewall: Ensure that your firewall is enabled and configured correctly to prevent unauthorized access to your laptop.
- Software Updates: Keep your operating system and all software applications up to date with the latest security patches.
- PIN Protection: Enable PIN protection for connecting to your laptop as a secondary display.
- Review Permissions: Carefully review the permissions requested by any screen sharing applications you install.
- Disable Features When Not in Use: When you’re not using your laptop as a secondary display, disable the feature to prevent unauthorized access.
Conclusion
Using another laptop as a second monitor is a cost-effective and convenient way to boost your productivity. While the process isn’t as simple as plugging in a dedicated external monitor, the methods outlined above provide viable solutions for both wired and wireless setups. Choose the method that best suits your needs and hardware capabilities, and remember to optimize performance and prioritize security. With a little bit of setup, you can transform that old laptop into a valuable asset for your workflow.
What are the main methods for using a laptop as a second monitor?
There are primarily two methods for using a laptop as a second monitor: using a physical connection via HDMI or USB, or utilizing wireless display technology. Wired connections, particularly with an HDMI capture card, offer a reliable and low-latency connection, ideal for demanding tasks like gaming or video editing. Software solutions like spacedesk or similar apps also rely on wired or wireless network connections to mirror or extend the main display to the secondary laptop.
Wireless methods like Windows’ built-in “Connect” feature (using Miracast) or third-party applications offer flexibility and convenience. These solutions allow you to avoid the clutter of cables and position the second screen freely within the Wi-Fi range. However, wireless connections are often more susceptible to latency and performance issues, especially with weaker network signals or older hardware. Choose the method that best suits your needs and available resources.
What hardware do I need to use a laptop as a second monitor?
The necessary hardware depends on the chosen method. For a wired connection via HDMI, you’ll need an HDMI capture card for the laptop you intend to use as a monitor. This allows the laptop to receive and display the video signal from your primary device. You’ll also need an HDMI cable to connect the two devices.
For wireless connections, you typically won’t need any additional hardware beyond the two laptops themselves. Ensure both laptops have Wi-Fi capabilities and support wireless display protocols like Miracast (often built into Windows). Some older laptops may require a wireless adapter to enable these features. Check your operating system’s compatibility documentation to confirm whether your devices support wireless display functionality.
How do I configure Windows to use a laptop as a second monitor wirelessly?
Windows provides a built-in feature called “Connect” that utilizes Miracast technology. On the laptop you want to use as a second monitor, open the Action Center (Windows key + A) and click on the “Connect” tile (you may need to expand the list of tiles). This will make the laptop discoverable as a wireless display.
On your primary device, also open the Action Center and click “Connect”. Select the name of the laptop you want to use as the second monitor from the list of available devices. Follow the on-screen prompts to establish the connection and configure display settings, such as mirroring or extending the desktop. You can adjust the display resolution and orientation through the Windows display settings.
What is spacedesk and how does it work?
spacedesk is a software solution that allows you to use another computer, laptop, tablet, or even a phone as a second display for your primary computer. It achieves this by turning the secondary device into a virtual display that is accessible over your local network (Wi-Fi or Ethernet).
To use spacedesk, you need to install the spacedesk Driver software on your primary computer (the one you want to extend the display from) and the spacedesk Viewer app on the secondary device (the laptop you want to use as a second monitor). Once installed and both devices are connected to the same network, the Viewer app will detect the primary computer, allowing you to connect and use it as an extended display.
What are the advantages and disadvantages of using a wired connection (HDMI capture card)?
The primary advantage of using a wired connection with an HDMI capture card is the low latency and stable connection. This makes it ideal for demanding applications like gaming, video editing, or any task where real-time responsiveness is crucial. Wired connections generally offer a more reliable and consistent experience compared to wireless solutions, minimizing potential disruptions and lags.
However, wired connections have disadvantages. They require purchasing an HDMI capture card, adding to the overall cost. Furthermore, the setup is less flexible due to the physical cable connection, limiting the placement of the secondary laptop. The capture card needs to be properly installed and configured, which may require some technical knowledge.
What are common troubleshooting steps if the second laptop isn’t detected?
If the second laptop isn’t being detected when using wireless display, first ensure that both laptops are connected to the same Wi-Fi network. Also, verify that wireless display is enabled on both devices. On the laptop being used as a second monitor, check the “Projecting to this PC” settings in the Windows settings app and ensure it’s configured to allow connections. Restarting both laptops can often resolve temporary connectivity issues.
For spacedesk or similar software solutions, ensure that the spacedesk Driver is running on the primary computer and the spacedesk Viewer is running on the secondary laptop. Check that the firewall isn’t blocking communication between the two applications. Make sure both devices are running the latest versions of the software. If issues persist, consult the software’s documentation or support resources for specific troubleshooting steps.
Will using a laptop as a second monitor significantly impact performance?
Using a laptop as a second monitor will likely have some impact on the performance of both the primary and secondary devices, but the extent of the impact depends on several factors. These factors include the connection type (wired vs. wireless), the resolution and refresh rate of the second display, and the demands of the applications running on both computers. Demanding tasks such as high-resolution video editing or gaming on the primary computer while simultaneously displaying intensive graphics on the second monitor will naturally consume more resources.
Wireless connections, especially over congested Wi-Fi networks, can introduce latency and potentially reduce frame rates, particularly on the primary device if it’s handling the rendering for both displays. A wired connection, especially with an HDMI capture card, minimizes the processing load on the primary computer. Lowering the resolution and refresh rate of the second monitor, as well as closing unnecessary background applications on both devices, can also help reduce the performance impact.