Today's work environment demands multitasking, but not everyone has the luxury of a second physical monitor. Often, an old or spare laptop is lying around, its screen sitting idle. Turning it into a secondary display for your main computer is an effective solution that expands your workspace without breaking the bank.
Fortunately, wireless data transmission technologies make this possible without the need for expensive cables. Using a Wi-Fi network eliminates the clutter of cables and provides flexibility in device placement. You don't need to be a networking expert to set up such a connection in just a few minutes.
There are several proven methods for implementing this idea, from built-in operating system functions to specialized software. The specific method you choose depends on the version of your Windows, local network speed, and required image refresh rate. In this article, we'll examine all available options in detail and help you choose the best one.
Preparation of equipment and network infrastructure
Before you begin software configuration, you need to ensure your hardware is ready to transmit a video stream. A stable wireless connection is key, as real-time image transmission requires significantly more bandwidth than regular internet surfing.
Both devices—the main PC and the receiving laptop—must be on the same local network. This means they must be connected to the same routerIf you are using a guest network or different frequency bands with client isolation, the connection may fail.
⚠️ Note: If your router operates in the 2.4 GHz band, image lag may be noticeable, especially when watching videos or working with graphics. For a comfortable experience, we strongly recommend using the 2.4 GHz band. 5 GHz.
It's also worth checking your wireless adapter drivers. Outdated network card software may not support necessary broadcast protocols, such as Miracast. Ensure that network discovery is enabled on both devices and data sharing is permitted.
Using the built-in "Project to this PC" feature
Starting with Windows 10, the operating system includes a native feature that allows you to use your laptop as a wireless monitor. This method doesn't require installing third-party software, making it the safest and fastest option for occasional tasks.
To start working on a laptop that will act as a second screen, you need to activate the receiving mode. Go to the menu Settings → System → Project to this PCIf the menu items are inactive, you may need to install an additional component via System Settings → Apps → Additional Components → Wireless Display.
Once the feature is activated, the laptop will go into standby mode. On the main computer, press the key combination Win + K to search for available devices. Your laptop should appear in the list that appears. After selecting a device, a connection request will appear on the laptop screen; confirm this.
☑️ Setting up a built-in projector
It is important to note that this method is highly dependent on technology support. Miracast From the Wi-Fi adapters of both devices. If one of the devices is old or has limited drivers, this feature may not work properly or at all.
Alternative solutions: Spacedesk and Splashtop
If standard Windows tools fail to cope or cause excessive delays, it is worth turning to specialized utilities. Programs like Spacedesk or Splashtop Wired XDisplay (which can also work via Wi-Fi) often show better performance and flexibility of settings.
They operate on a similar principle: a driver emulator is installed on the host computer (the server), and a viewing application is installed on the laptop (the client). These programs use proprietary video compression algorithms, which reduces network load and latency.
⚠️ Important: When using third-party software, ensure that Windows Firewall isn't blocking incoming connections for the new application. When you first launch the application, the system may ask for network access permission. Select "Private network" or "Allow access."
One of the main advantages of such programs is the ability to fine-tune image quality. You can sacrifice color for speed (16-bit mode) or, conversely, enable lossless compression for working with text. Multi-touch support is also often available, allowing you to use your laptop's touchscreen to control your main computer.
Why might Spacedesk not see my computer?
Often, the problem lies with your antivirus settings or network type. Make sure your current network in Windows is marked as "Private" and not "Public." On public networks, Windows hides your computer from detection by other devices by default. Also, check that Bonjour or similar services aren't blocked by your firewall.
Comparison of connection methods: characteristics table
To help you choose the right tool, we've prepared a comparison chart of the main methods. It will help you evaluate the tradeoffs between image quality, latency, and setup complexity.
| Method | Latency | Picture quality | Difficulty of setup |
|---|---|---|---|
| Built-in (Miracast) | Average | High | Low |
| Spacedesk | Low/Medium | Flexible | Average |
| Splashtop | Low | High | Average |
| TeamViewer/AnyDesk | High | Average | Low |
As can be seen from the table, the built-in method is ideal for static work with documents or SpacedeskIf you need minimal latency for dynamic content, it's worth experimenting with bitrate settings in third-party utilities.
Performance optimization and lag elimination
Even with a perfectly configured software, your wireless connection can suffer from interference. If you notice your cursor becoming out of sync or the image is choppy, first check your Wi-Fi bandwidth. In apartment buildings, the airwaves are often clogged with signals from neighboring routers.
Try changing the router's broadcast channel to a less congested one. Another effective method is moving your laptop closer to the router or using a USB extender to extend the Wi-Fi antenna if it's external. Physical obstacles, such as walls and metal structures, also affect the 5 GHz signal.
In the graphics settings of your main computer, you can try reducing the screen refresh rate for the second monitor to 30 Hz or 50 HzIf 60 Hz causes instability, this will reduce the load on the data transmission channel. Additionally, disabling hardware acceleration in the browser on the receiving device can free up resources for decoding the video stream.
Common problems and solutions
Despite the simplicity of the concept, users often encounter typical errors. The most common one is "Device not found." This is usually resolved by checking the network type mentioned earlier or restarting the Windows Connect Now Device Manager service in Windows Services.
Another problem is low brightness or incorrect resolution. In this case, you need to go to Settings → System → Display on the primary PC and manually set the recommended resolution for the second screen. Keep in mind that scaling (e.g., 125% or 150%) on different monitors can cause blurry fonts in some older applications.
⚠️ Note: Operating system and driver interfaces are constantly updated. The location of menu items or service names may vary depending on the Windows build version or graphics card manufacturer. If the exact path doesn't match, look for similar settings.
If you see an image but no sound, check your playback devices. In the Windows system tray, click the speaker icon and select the audio output device corresponding to your virtual monitor or laptop speakers.
Summary and recommendations for choosing a use case
Using a laptop as a second monitor via Wi-Fi is a great temporary or even permanent solution for expanding your desktop. It saves money, eliminates unnecessary cables, and allows for flexible workspace configuration.
For regular work with text and spreadsheets, built-in Windows tools are most convenient. For more specific tasks where performance is critical, it's better to install specialized software. A good network connection is crucial, as it's the bottleneck for the entire system.
Now that you know, How to turn a laptop into a second monitor for a PC via WiFi, you can effectively use your existing equipment. Experiment with the settings to find the balance between image quality and smooth operation that suits you.
Can I use my tablet as a second monitor?
Yes, the principle is absolutely identical. You can also install client apps (Spacedesk, Splashtop) on Android or iOS tablets, turning them into fully functional additional displays. Control is often even more convenient thanks to a touchscreen.
Do I need internet access to use a second monitor via Wi-Fi?
No, internet access is not required. All devices need to be connected to a single local router (even without internet access). The entire video stream is transmitted within your home network.
Does this affect internet speed?
The image transfer process itself doesn't use any internet bandwidth; it only loads the local Wi-Fi network. However, if the router is weak, the overall network data transfer speed may drop, which indirectly affects page loading speed.
Why is the picture on the second screen blurry?
This is most often a Windows scaling issue. Try setting the same scaling percentage (e.g., 100%) on both screens or adjusting ClearType settings to smooth fonts.
Is it possible to stream audio to a laptop?
Yes, most modern methods (including built-in Miracast and Spacedesk) allow audio transmission. To do this, select the appropriate audio output device in Windows settings.