How to Use a Laptop as a Wireless Second Monitor in Windows 10 and 11

What the author did​

Alvi says he already uses a 27-inch monitor at his desk and a portable monitor for travel. The old laptop is a third option he uses occasionally. He says it's bulkier, so it sees less use. He found the setup easy and free, but he is clear that a real monitor gives better image quality and lower latency.

Those impressions are his own experience. Microsoft doesn't promise that setup is instant or that it will feel like a wired display.

Which PC does what​

Alvi's text blurs this, so it's worth stating plainly:

• The old laptop is the receiver. It's the PC you project to, and it becomes the screen.
• The main PC is the sender. It's the PC you project from.

Microsoft's instructions put the Wireless Display installation and launch steps on the receiving PC. The sending PC starts discovery. On the PC you're projecting from, you press the Windows logo key + K and select the PC you want to connect to.

Step-by-step: set up the laptop as the receiver​

On Windows 11 (the laptop that will act as the screen):

1. Open Start, then Settings, then System, then Projecting to this PC.
2. Under "Add the 'Wireless Display' optional feature to project to this PC", select Optional features.
3. Next to Add an optional feature, select View features and enter "wireless display."
4. Tick Wireless Display, select Next, then Install.
5. When installation finishes, select Back to manage your projection preferences on the Projecting to this PC page.
6. Launch the Wireless Display app by entering "wireless display" in the taskbar search box and selecting it from the results.

Microsoft's note on versions: the Wireless Display app is available on Windows 11 version 22H2 and later. On earlier Windows 11 builds, you launch the Connect app instead.

On Windows 10 (the laptop that will act as the screen):

The path is the same: Settings, System, Projecting to this PC. Then select Add a feature and enter "wireless display." Install it, then launch the Connect app from the taskbar search.

Connect from the main PC​

1. Make sure the receiver is awake with the Wireless Display or Connect app open.
2. On the main PC, press Windows key + K.
3. Select the laptop from the list.
4. Approve any prompt on the receiver. A community walkthrough on Windows 11 Forum notes that the receiving PC may ask whether to allow or block the projection.
5. Press Windows key + P and choose Extend.

Microsoft's display-mode menu has four options: PC screen only, Duplicate, Extend and Second screen only. Microsoft says that with Extend, you can move items between the two screens. Choose Extend if you want a second workspace. Duplicate just shows the same picture twice.

Alvi also suggests using Display settings to identify each screen and drag the displays into the same arrangement as your desk. That is a good tip. It keeps your mouse from "escaping" off the wrong edge.

The catch: not every old laptop can do this​

Alvi says "anyone, literally anyone" can do this with no extra hardware. That is too strong. He does later say the laptop needs to support Miracast, and that qualifier matters.

• Microsoft's driver documentation describes Miracast as a standard built on Wi-Fi Direct. It uses a peer-to-peer connection between the source and the display. Installing the Wireless Display feature doesn't add that capability to hardware that lacks it.
• Microsoft's guidance for PC makers says the Miracast stack needs a WDDM 2.0 or newer graphics driver. The sender's graphics hardware must also support hardware-accelerated H.264 encoding. Microsoft also recommends 5GHz Wi-Fi for higher stream quality.
• In a Microsoft Q&A answer, a missing Wireless Display option is tied to hardware limits. If Windows says an external display must be connected with a cable, the device likely doesn't support Miracast.

A quick check is to run netsh wlan show drivers in Command Prompt and look for a "Wireless Display Supported" line. The research brief for this story cites Microsoft's driver documentation for that check. The Microsoft Learn page I could review doesn't spell the command out, so treat it as a handy test rather than an official pass/fail rule.

Troubleshooting: laptop missing from the Win + K list​

Microsoft's own advice is short: make sure the receiving PC has Wi-Fi turned on and has the wireless display app installed and launched. Beyond that:

• Confirm the Wireless Display or Connect app is actually open on the laptop. Techdows says that without the app launched, the PC isn't discoverable.
• Update the Wi-Fi and graphics drivers on both machines, then check Optional features again. Microsoft Q&A answers suggest this when the feature is missing.
• If the feature won't install or launch on Windows 11, a third-party guide suggests removing and re-adding it. Treat that as community advice, not a Microsoft fix.
• On Windows 11 N editions, one third-party guide says the feature may not appear. Check your edition and version.
• On a work-managed PC, administrators can restrict projection through policy. The research brief cites Microsoft's Wireless Display policy documentation for that.

Windows 10 is now out of support​

Alvi's receiver runs Windows 10. That deserves a caveat today. Microsoft's support page says support for Windows 10 ended on October 14, 2025. After that date, Microsoft stopped providing free updates from Windows Update, technical assistance and security fixes. The PC still works, but Microsoft recommends moving to Windows 11.

The setup still functions. But a laptop on an unpatched OS shouldn't carry sensitive work or sit on an untrusted network. Using it only as a display doesn't restore its security updates.

Expectations and a few notes on HDMI​

• Performance: Microsoft's manufacturer guidance says a wireless projection stream must be created, delivered and rendered in real time. Quality depends on the Wi-Fi, graphics and audio components. An older laptop may therefore lag. It's fine for chat windows, reference docs or a dashboard. It's a poor fit for fast video editing or gaming.
• HDMI: Alvi says laptop HDMI ports are for output, not input. That is true of most laptops. Check your specific model before assuming it can accept video in.
• Cost: The feature is free, and you don't open either machine. The laptop stays usable for other jobs.

Bottom line​

If both PCs support Miracast, this is a practical, no-cost way to get extra screen space from hardware you already own. Install Wireless Display on the laptop, launch it, press Win + K on the main PC, then choose Extend. If the laptop never shows up, the most likely cause is missing Miracast support, not anything you did wrong. In that case, a cheap used monitor will serve you better.