Many users are faced with a situation where the main monitor is not enough for comfortable work, and the purchase of new equipment is not included in the current budget. In such cases, you often have an old or additional laptop at hand, the screen of which seems simply useless if it is not used as a stand-alone device. In fact, use laptop as monitor It's entirely possible, and it can greatly expand your workspace without breaking the bank.
However, it is important to immediately understand a technical nuance: most ports on a laptop body, including HDMI, are designed solely for outputting images and not for receiving signals. This means that simply connecting a cable from the system unit to the video input of the laptop will not work in 95% of cases. To implement your plans, you need to use special software protocols or specific hardware, which will be discussed in this article.
Windows built-in screen extension tools
The easiest and free way to get a second display is to use the “Wireless Monitor” function built into the Windows 10 and 11 operating system. This technology works using the Miracast protocol and allows you to transmit a video stream over Wi-Fi without the need to install third-party software. To do this, on a laptop that will play the role of a second screen, you need to open Settings → System → Project to This PC.
It's important to check that the feature is available, as it may be disabled by default on some devices or may not be supported by an older Wi-Fi adapter. If the option is greyed out, you will need to install the Wireless Display component via Settings → Applications → Additional components. After activation, you will be able to see the laptop in the list of available devices on the main PC.
The connection process is as follows: on the main computer, click Win + P and select "Connect to a wireless display." Your laptop's name will appear in the list. Once connected, the image is duplicated or expanded depending on the settings selected.
⚠️ Attention: Wireless image transmission via Miracast has a delay (lag) of 50-200 milliseconds, which makes this method unsuitable for dynamic games, but quite comfortable for working with text, tables and watching videos.
- ✅ Requires Wi-Fi adapters supporting Miracast on both devices.
- ✅ Support only works within the same local network or with a direct connection.
- ✅ Setup does not require installation of additional drivers if the system is updated.
The built-in Windows feature is the most accessible method, but it critically depends on the quality of the Wi-Fi connection and can cause a noticeable image delay.
Third-party programs for a stable connection
If the built-in Windows tools are unstable or are not supported by your hardware, specialized utilities come to the rescue. Programs like Spacedesk, Duet Display or Synergy use a network connection (Wi-Fi or USB) to create a virtual video driver. This allows you to turn your laptop screen into a full-fledged workspace with minimal delays.
The most popular solution among users is Spacedesk, since it is completely free and works perfectly over a local network. You need to install the server part on your main PC, and the client part on your laptop. Once both applications are launched, they automatically discover each other if they are on the same network.
For mission-critical applications where every millisecond of response matters, it is better to use a USB cable connection. In the program settings Duet Display You can switch the data transfer mode from wireless to wired, which significantly improves picture clarity and cursor smoothness. This is especially true for designers and those who work with graphics.
What to do if the program does not see the laptop?
Make sure the Windows firewall is not blocking the connection. Make sure network discovery is enabled on both devices. Try disabling VPN connections if they are active.
Using third-party software opens up the possibility of fine-tuning the resolution and refresh rate. You can ask 1920×1080 at 60 Hz or even lower if the network is congested. This gives you flexibility not available in standard Windows settings.
- 🛠️ Spacedesk — ideal for office tasks and working with documents.
- 🛠️ Duet Display — a paid solution with the best optimization for drawing and video editing.
- 🛠️ Synergy - Allows you to use one mouse and keyboard to control multiple PCs, but does not share the screen.
☑️ Preparation for connection via software
Hardware method: Video capture card
If you need to connect your laptop to a gaming console or powerful PC to stream games with minimal latency, software methods will not work. The only reliable way is to use an external video capture cards (Video Capture Card). It's a small device that converts an HDMI signal to USB, tricking your laptop into thinking the external source is a webcam.
To implement this method, you will need a capture card with a USB 3.0 interface (preferably with support for 4K or at least 1080p at 60 Hz). Popular models from brands Elgato or Chinese analogues for 1500-2000 rubles do an excellent job of this task. The connection is carried out according to the following scheme: PC → HDMI cable → Capture card → USB port of a laptop.
After connecting the card, you need to open the camera application on your laptop (for example, the standard “Camera” in Windows or OBS Studio). Your capture card will appear in the list of video input devices. You will see the image from the external PC in the program window. For convenience, you can expand the window to full screen.
⚠️ Attention: Cheap USB 2.0 capture cards may produce images with a 0.5-1 second delay and low resolution, which makes them unsuitable for dynamic games, but acceptable for viewing static content.
This method is completely independent of the quality of the Wi-Fi network and works as stably as any other USB device. The delay is minimal and almost invisible to the eye when using high-quality models with USB 3.0 support.
- 🔌 Requires the purchase of additional equipment (capture cards).
- 🔌 Works with any output devices: consoles, PCs, TV set-top boxes.
- 🔌 Provides the most stable picture without freezing.
A capture card is the only way to use a laptop screen to play games on consoles or high-end PCs with acceptable latency because it operates at the hardware signal level.
Comparison of methods and selection of the optimal solution
To finally decide on the method, let's compare the key characteristics of each of the methods considered. The choice depends on what tasks you plan to solve: working with text, watching videos or playing games. Each technology has its pros and cons, which can be the deciding factors.
Below is a table that clearly demonstrates the differences in performance and requirements:
| Method | Delay | Requirements | Cost | Ideal for |
|---|---|---|---|---|
| Windows Miracast | High (100+ ms) | Wi-Fi adapters | Free | Documents, browser |
| Third party software (USB) | Medium (30-50 ms) | USB 3.0 cable | Free/Paid | Office, graphics |
| Third party software (Wi-Fi) | Network dependent | Local network | Free/Paid | Videos, presentations |
| Capture card | Low (<20ms) | HDMI Capture Card | 1500-15000 rub. | Games, consoles |
- Free Wi-Fi (Miracast)
- Third party software via cable
- Video capture card
- I won't use a laptop
If savings are important to you and you work with documents, then software solutions are the best choice. They do not require investment and are easy to set up. However, for gamers or those who stream content, skimping on hardware can result in a loss of performance and comfort.
When using a capture card in OBS Studio, be sure to disable “Auto-detect” in the video source settings if you have color rendering problems, and manually set the correct signal format (YUV or RGB).
Nuances of setting resolution and frequency
Once the connection is established, a problem often arises with the screen resolution being incorrect. The laptop may be detected as a low-resolution device, causing text to appear small or blurry. In Windows display settings (right click on desktop → Screen Options) you need to manually set the desired resolution, for example, 1366×768 or 1920×1080, depending on the matrix of your laptop.
The refresh rate also plays an important role. By default, the system can set 30 Hz, which makes the mouse movement jerky. Change this setting to 60 Hz in section Additional display options. This will make the interface much smoother, although it may require a little more bandwidth.
Pay special attention to the location of the screens. On the menu Screen Options drag the rectangles representing your displays into the actual physical position. This will allow the mouse cursor to move from one screen to another naturally, without having to make unnecessary movements.
⚠️ Attention: If you use the laptop as a monitor, do not close its lid unless you have configured the appropriate power mode (“When closing the lid” → “No action required”), otherwise the laptop will go into sleep mode and turn off the screen.
Sometimes graphics card drivers on your main PC can conflict with virtual displays. In such cases, it is recommended to update the drivers to the latest version or use specialized utilities for managing monitors, such as DisplayFusion.
Compatibility problems and their solutions
Sometimes users encounter the fact that the laptop is not recognized as a monitor. This may be due to outdated Wi-Fi adapter drivers or lack of Miracast support. Check for support through the team dxdiag: in the window that opens, go to the “System” tab and find the “Miracast” line.
If there is no support, the laptop will not be able to work as a wireless monitor through standard Windows tools. In this case, the only option is to use an external USB adapter for wireless transfer or purchase a capture card.
Another common problem is lack of sound. When transferring an image, the sound often remains on the main computer. In the Windows audio settings on your main PC, select the output device that matches your second screen (or virtual driver) to play audio through your laptop speakers.
- 🔍 Check the version of Wi-Fi and video card drivers on both devices.
- 🔍 Make sure that both devices are on the same subnet (same router).
- 🔍 Restart both computers after updating the drivers.
Lack of Miracast support is a common problem on older laptops, which can only be solved using external adapters or software solutions that work via USB.
FAQ: Frequently asked questions from users
Is it possible to connect a laptop to a PC via HDMI cable directly?
No, in the vast majority of cases this is not possible. HDMI ports on laptops are output ports and cannot receive input signals. For this you need a capture card.
Which method is best for gaming?
The best option is to use a video capture card. Software methods via Wi-Fi provide too much latency for comfortable gaming.
Will this method work if the laptop does not have access to the Internet?
Yes, a local network does not require access to the global Internet. The main thing is that both devices are connected to the same router or a direct connection is created between them.
Can I use my laptop screen to stream from a console?
Yes, the capture card method is ideal for this. Connect the console to the card, and the card to the laptop, and you can see the console image on the laptop screen.
Why is the image on the second screen blurry?
Check your resolution settings in Windows. Make sure you select your laptop's native display resolution and not upscaled or standard low resolution.