Use your tablet/phone/practically any other device as a second monitor for a Windows computer

We are leaving in a couple days to visit my father-in-law. I want to work while on this trip, including getting my online courses ready for the fall*. Now that I routinely work with three monitors, the thought of trying to ready my courses with only my Windows laptop monitor made me a little twitchy. I travel with a small Android tablet, so surely there must be an easy way to extend my Windows laptop to that tablet as a second screen – easier that the software I used a few years ago. And there is.

Spacedesk is free.

Your Windows computer will be your primary machine. This is the computer you’re going to be working on.

Your secondary machine – the one that will just be acting as a monitor for your primary machine – can be just about anything: Android (tablet, phone), Apple (Mac, iPad, iPhone), Windows (laptop, computer), or whatever can run a modern web browser (including Linux). The device has to be able to connect either to the same wifi network as your primary machine or connect by cable to each other. Spacedesk recommends cable for a faster, more stable connection. With my devices connected via wifi, I haven’t noticed any connection or speed issues.

These instructions will be for connecting an Android device, but the Spacedesk documentation seems to cover every contingency.

Installation

On your primary device (for me, that was my Surface), download Spacedesk. You’ll need to know if your Windows computer is 32-bit or 64-bit. You can guess, and if you guess wrong, when you try to install Spacedesk, it will tell you that you need the other one. Or you can find this information pretty easily on your computer. Right-click on the Windows logo in the bottom-left corner of your screen – the symbol that gives you your start menu when you left-click on it. After right-clicking, from the menu, choose “System.” In the “Device specifications” section – about the middle of the page – next to “System type” it will say 32-bit or 64-bit.

After downloading the correct 32-bit or 64-bit software, double-click on the downloaded software. Click through the install screens. Your primary device is now ready to go.

Now you need to install Spacedesk on your secondary device (for me, that was my Android tablet). If you’re also installing on Android, on your Android device, go to the Google Play Store, and search for Spacedesk; install it, and run it. If you’re installing on an an iPad or other Apple device, use that device to search for Spacedesk in the App Store; install it, and run it. If you want to use a different device as a secondary monitor, please see the Spacedesk documentation – look for “Spacedesk Viewer Software for Secondary Machine.” Their instructions are very well-written.

Connecting your secondary monitor

After installing Spacedesk on your primary device, Spacedesk will automatically be on. Run Spacedesk on your secondary device, and if the two devices are on the same network, you’ll see the name of your primary computer pop up on the screen of your secondary device. Click on “Connection”, and the two devices will be connected.

Placing your secondary monitor

On your secondary monitor, you will see your primary device’s desktop. To use it, you will drag windows off your primary computer’s screen and onto your secondary monitor’s screen. To do that, you need to tell your primary computer where that secondary monitor is.

On your primary computer, go to its display settings. The easiest way to do that is type “change display settings” in the bottom search bar and press enter. At the top of the screen you will see a couple boxes with numbers in them. Those represent the monitors your primary computer can see. Where they are in relation to each other on the screen is where Windows thinks they are in relation to each other on your table. Click the “Identify” button. Big numbers will appear on each of your monitors. If you only have two monitors (your primary device and your secondary monitor), your primary computer screen will be 1 and your secondary monitor will be 2.

On your table, set your secondary device wherever it will be most convenient for you to use, say, to the left of your laptop. On the display settings screen, click and drag the #2 box to the left of the #1 box. Click the “Apply” button.

Now you’re ready to use your secondary monitor! Click and drag any window off your primary computer’s screen to the left – if that’s where you put your secondary monitor – and the window will appear on your secondary device. How cool is that?

Disconnecting your secondary monitor

When you’re ready to disconnect your secondary monitor, in your primary computer’s taskbar (bottom-right corner of your screen), right-click on the Spacedesk icon (you may need to click the ^ symbol to see the Spacedesk icon), and select “OFF”. Your secondary device will display a pop-up that says “Display disconnected by server.” Click “OK”. Your secondary device’s Spacedesk app will still be trying to find your primary computer to connect. Just close that app. On Android, clicking Android’s back button will close the app.

Sometimes when I would mouse over the Spacedesk taskbar icon, I would get a little Spacedesk pop-up, and because of where it was located I couldn’t right-click on the icon. Solution? I told Windows to always display the Spacedesk taskbar icon so I don’t have to click the ^ symbol to see it. To do that, search your computer for “Select which icons appear on the taskbar”. On the screen, scroll down until you find “SpaceDeskServiceTray.exe”. Click its button from “Off” to “On”. Close the screen. Now the Spacedesk taskbar icon will always be where you can easily right-click on it to turn it off and on.

Reconnecting your secondary monitor

Make sure both devices are connected to the same network. In your primary computer’s taskbar, right-click on the Spacedesk icon, and select “ON”. On your secondary device, run the Spacedesk app. Click “Connection” under the name of your primary computer, and you’re back in business!

Your primary computer should remember where you put your secondary monitor the last time you used it. If you’re putting your secondary monitor somewhere else, return to the “Change Display Settings” screen on your primary computer, move the secondary monitor box to wherever you’d like it to be. Click “Apply”.

Have multiple devices?

Yes, you can add Spacedesk to other devices and have multiple monitors. The top one is my main monitor. I can drag a window down to display it on my phone. Or I can keep dragging it down and display it on my tablet.

Word of caution about public wifi

If you are connecting all of your devices to public wifi, such as at your local coffee shop, you’re open to security risks. I recommend using a VPN, such as “Private Internet Access” for an important layer of password-protected security between you and everyone else who is on that wifi network. If you connect your laptop and your tablet to a VPN, however, they’re no longer really on the same network. They’re on the same wifi, but they’re being routed through different secure servers, so the devices don’t know they are on the same network. If they don’t know they’re on the same network, Spacedesk can’t connect them.

Public WIFI Option 1: Use the Windows 10 built-in mobile hotspot feature to connect your other devices to your laptop.

First, connect your laptop to the public wifi and run your VPN. Now your laptop is secure.

Use your Windows search box to find “Change mobile hotspot settings”. Set the “Share my Internet connection with other devices” to “On.” You’ll see the network name and password. You can change those by clicking the “Edit” button.

On your tablet or phone, you’ll see your Windows mobile hotspot name as one of the possible wifi networks you can connect to. Connect to it using the password in the Windows mobile hotspot settings. Once connected, you can now run the Spacedesk software knowing that all of your wifi-connected devices are behind a password-protected wall.

Public WIFI Option 2: Use a travel router.

I use the TP-Link N300 Portable Nano Travel Router. When I travel, I connect the travel router to the public wifi using my laptop. Once connected, it displays a password-protected wifi network that all of my devices have connected to before. Once the network is up, my tablet and my phone automatically connect to that same password-protected network – just like they do when connecting to my home network. With everything connected to same secure network on the road, I can use Spacedesk to create my second (or third) monitors.

I most often use this setup in my hotel room. The router stays on all the time. When I get back to the room, all of my devices automatically connect to the router’s wifi.

Be productive on the road, but stay safe.

*Getting my courses ready for the fall – to my semester-going colleagues, we’re on quarters, so classes don’t start next week. They start the last week of September. I’m not that far behind!