Guide · updated 16 October 2026

How to use an Android tablet as a second monitor on Windows

By Yossi Oknin, developer of extraDisp

What you need

Step 1: Install the Windows server

1. Download XDisp-Portable.zip and extract it to a folder you will keep, for example C:\Tools\XDisp.
2. Run XDisp.exe. If SmartScreen says "Windows protected your PC", click More info, then Run anyway.
3. If Windows Defender Firewall asks, allow access on private networks. The tablet connects to the PC on port 8765, so a blocked firewall stops Wi-Fi mode.

The server window has four parts: Server Settings (port, monitor, quality, FPS), the Start Server and Remote Control buttons, Extend Display (the virtual display buttons) and a Status panel with the address, USB state and connected clients.

Step 2: Give Windows a second display

extraDisp streams one monitor to the tablet. To get an extended desktop, Windows needs a monitor that doesn't exist yet. Without one, the tablet mirrors a screen you already have.

1. In the Extend Display box, click Setup Virtual Display.
2. The server downloads the latest release of the open-source IddSampleDriver from GitHub and asks for administrator approval to install it. Click Yes.
3. When the status reads "Virtual display ready!", a 1920 × 1080 monitor has been added. If it says Windows hasn't detected the driver yet, restart the PC and click Add.
4. Open Settings > System > Display. Make sure it says Extend these displays, then drag the new display to the side of your main monitor where the tablet sits.

Prefer hardware? A headless HDMI dummy plug in a free GPU port also gives Windows a second monitor, and extraDisp can stream it the same way.

Step 3: Pick the monitor and start the server

1. Click the refresh button next to Monitor, then pick the new display from the list. It shows each monitor's size, such as "Monitor 2 (1920x1080)".
2. Set Quality (10 to 100, default 70) and FPS (1 to 60, default 30). The defaults are a good start; you can change both from the tablet later.
3. Click Start Server. The status turns to "Server Running" and shows a line like Listening on: 192.168.1.20:8765. Note that address for Wi-Fi.

Step 4a: Connect over Wi-Fi

1. Open extraDisp on the tablet. It shows "Scanning for servers..." and, if it finds a PC under Discovered, connects to the first one by itself.
2. If nothing shows up after a few seconds, type the address from the server window into Server address and tap Connect. If you leave out the port, the app adds 8765.
3. The desktop of the chosen monitor fills the tablet in landscape. The address is saved under Recent, so next time it is one tap away.

Step 4b: Connect over USB

USB mode uses adb, Android's debugging bridge. You set it up once.

1. Install adb on the PC. Download Google's Android SDK Platform-Tools and either add the folder to your PATH or extract it to %LOCALAPPDATA%\Android\Sdk\platform-tools. extraDisp Server looks in both places.
2. Turn on USB debugging on the tablet. Open Settings > About tablet and tap Build number seven times to unlock Developer options. Then open Developer options and switch on USB debugging.
3. Plug in the cable and tap Allow on the "Allow USB debugging?" prompt. The server's Status panel shows "USB: 1 device(s) connected".
4. Click Start Server. The server keeps the tablet awake while plugged in, wakes and swipes the screen, runs adb reverse tcp:8765 tcp:8765 and opens extraDisp connected to localhost:8765. You don't touch the tablet.

A screen lock with a PIN, pattern or password still needs you to unlock it once; the swipe only clears a plain swipe lock.

Optional: launch over Wi-Fi with wireless ADB

With the cable still connected, click Enable WiFi ADB. The server switches the tablet's adb to port 5555 and saves its Wi-Fi address. After that you can unplug, start the server and click Connect WiFi: it wakes the tablet and opens extraDisp pointed at the PC's network address.

Step 5: Adjust the picture from the tablet

Tap the small gear in the bottom-right corner of the tablet to open the settings sheet.

• Monitor: switch which Windows monitor is streamed.
• Resolution: change the streamed monitor's resolution to any mode it reports. Pick one close to the tablet's shape so it fills the screen.
• Quality: JPEG quality in steps of 10, from 10 to 100.
• FPS: 1 to 60 frames per second.
• Disconnect: stop and go back to the connect screen. The back button asks first.

Touch works as the mouse on that screen: a tap is a left click, a drag is click-and-drag, and a swipe sends mouse-wheel scrolling. There is no on-screen keyboard; type with the PC's keyboard.

Wi-Fi or USB: which should you use?

Common problems and fixes