What Is Windows 10 S, and How Is It Different?

Windows 10 S is “the soul of today’s Windows”, according to Microsoft. It’s a new version of Windows intended for school PCs, but available to everyone. It’s designed to be more simple and streamlined, so it only runs applications from the Windows Store—unless you spend another $50 to upgrade to Windows 10 Pro.

Microsoft announced that Acer, Asus, Dell, Fujitsu, HP, Samsung, and Toshiba will ship Windows 10 S education PCs starting at $189, beginning this summer. Microsoft is also releasing a $999 Surface Laptop, which runs Windows 10 S.

This article was originally written based on the information Microsoft released at its May 2, 2017 event, but has since been updated with new information we’ve learned.

How Is Windows 10 S Different?

The biggest difference in Windows 10 S is that can only run apps downloaded from the Windows Store. These apps are checked for security and run in a secure container. This ensures that applications can’t mess with your registry, leave files behind, or cause problems with the rest of your PC. You can get the same benefits by running those new Universal apps from the Windows Store on a Windows 10 PC. But unlike normal Windows 10, you won’t have the option of downloading other apps that aren’t available in the store.

Thankfully, full versions of Microsoft Office 365 applications—Word, Excel, PowerPoint, Outlook, and OneNote—are coming to the Windows Store soon. They’re packaged using Microsoft’s Project Centennial, which allows traditional Windows desktop applications to be run in a secure container and placed in the Windows Store. The application’s developer just has to package the application and submit it to the Store. Hopefully, Windows 10 S will give more desktop application developers the push to do so.

Microsoft demonstrated Windows 10 S signing in much faster than Windows 10 Pro on a first login. That’s no surprise, as Windows 10 S won’t have all the usual manufacturer-installed bloatware slowing things down.

Windows 10 S also has a different default desktop background that Microsoft says is “streamlined” like Windows 10 S itself, so it provides you with a clue you’re using Windows 10 S.

What Happens if You Download a Desktop App in Windows 10 S?

If you try to download a (non-Store) desktop application on a Windows 10 S PC, you’ll see a message saying that “For security and performance, Windows 10 S only runs verified apps from the Store”. The dialog informs you of similar applications available in the Windows Store. For example, Windows will suggest you install Adobe Photoshop Express from the Windows Store if you try to download the desktop version of Photoshop.

In this way, Windows 10 S’s default behavior works just like Windows 10 with the “Allow apps from the Store only” option enabled. This will also protect those PCs from malware.

Windows 10 S Offers Some Pro Features, But No Command Lines

Windows 10 S is actually built on Windows 10 Pro, and not Windows 10 Home. This means that Windows 10 S has access to powerful Windows 10 Professional features, including BitLocker drive encryption, the ability to join domains, and the Hyper-V virtual machine software.

However, the advanced features stop there. Windows 10 S is more limited in other ways.

Windows 10 S won’t allow any access to command line environments or tools. You can’t launch either the Command Prompt (CMD) or PowerShell environment. This version of Windows does not include the Windows Subsystem for Linux, either. You can’t install Bash-on-Linux environments like Ubuntu, openSUSE, or Fedora from the Windows Store.

As Microsoft points out, all command line tools run outside the “safe environment” that normally protects the system from malicious or misbehaving applications.

You Have to Use Bing and Microsoft Edge

You have to use Microsoft Edge on Windows 10 S. You can’t change your default browser, and you can’t even install Google Chrome or Mozilla Firefox. Those are desktop applications, and aren’t available in the Windows Store.

Microsoft Edge also has a big limitation on Windows 10 S: You can’t change its default search engine. Bing will always be the default. This is a big departure even from Chromebooks, which allow you to choose any search engine you like.

Microsoft noted that “Windows 10 S can run any web browser in the Windows Store” at its May 2 event. That just includes Microsoft Edge right now, but Microsoft clearly wants Google and Mozilla to create browsers for the Windows Store, too.

However, Microsoft is being a little sneaky here. Microsoft won’t let Google package Chrome for the Windows Store, even if Google wanted to. The Windows Store only allows browser apps based on the Edge browser engine, just as Apple’s iPhone and iPad App Store only allows browsers built on the Safari browser engine. You’ll only get a Chrome browser for Windows 10 S if Google creates a new version of Chrome based on Edge (like Google does with its Safari-based Chrome for iOS).

But even if Google did create a version of Chrome based on Microsoft Edge, you wouldn’t be able to make it your default browser anyway.

Microsoft didn’t mention these limitations in its presentation, and they were only discovered in the Windows 10 S FAQ and Windows Store Policies afterwards.

How to Upgrade to Windows 10 Pro

You can upgrade any Windows 10 S device to Windows 10 Pro to enable running desktop applications on it. The upgrade process happens through the Windows Store and works just like upgrading from Windows 10 Home to Pro.

Schools can upgrade their PCs for free, while everyone else can pay $50 to unlock Windows 10 Pro and the full Windows desktop experience.

However, Microsoft will allow anyone who uses “assistive technologies” to upgrade from Windows 10 S to Windows 10 Pro for free. Assistive technology tools like screen readers are generally only available as desktop applications and aren’t in the Windows Store, so it makes sense.

Microsoft still allows anyone to upgrade from Windows 7 or 8 to Windows 10 for free using this same reasoning—you just need to click a button saying they use assistive technology. The Windows 10 S upgrade offer looks similar. Microsoft is using the honor system, once again.

Who Is Windows 10 S For?

Windows 10 S computers are Microsoft’s answer to Chromebooks, which are also big in schools. Chromebooks can only run web-based software, while Windows 10 S can also run powerful desktop apps if they’re packaged for the Store. In this context, Windows 10 S doesn’t look too limited—it looks more powerful than Google’s Chromebooks…as long as Windows developers get on board with the store. Of course, Chromebooks can now run Android apps, so they’re getting more powerful too.

Microsoft is positioning Windows 10 S as a streamlined version of Windows 10 for schools. They even showed off a simple “Set Up My School PC” application that creates a USB drive which will automatically set up PCs with the settings. Plug in the USB drive, wait 30 seconds, and the system will be configured automatically. Then, plug the USB stick into the next laptop.

In addition to the Surface Laptop, which is Microsoft’s flagship Windows 10 S device and only available with Windows 10 S, Microsoft is working on Windows 10 S versions of its Surface Pro and Surface Book hardware. These won’t replace the Surface Pro and Surface Book models with full versions of Windows, but these Windows 10 S versions will be available to schools looking for locked down Surface devices that aren’t laptops.

But Windows 10 S isn’t just for schools. Microsoft expects Windows 10 S will be available on normal consumer PCs. You’ll probably see Windows 10 S PCs in stores alongside normal Windows 10 PCs. And hey, if you try it and don’t like it, you can always turn a Windows 10 S PC into a Windows 10 Pro PC for $50. That’s actually cheaper than the upgrade from Windows 10 Home to Pro, which costs $100.

Chris Hoffman is a technology writer and all-around computer geek. He's as at home using the Linux terminal as he is digging into the Windows registry. Connect with him on Google+.