Some laptops come with Windows 10 S, such as the Surface Laptop. It looks and runs like normal Windows with one exception: you can install apps only from the Microsoft Store.
If you need to install something that isn't available there, such as the Google Chrome web browser, you will see an error message saying that you're not allowed to do that and the installation will be blocked.
But the good news is that you can switch out of S mode and into the full Windows 10. It's simple and quick to do, and here's what you need to do.
Switch out of Windows 10 S mode
Choose Settings from the Start menu - the cog icon just above the power button - and then navigate to Update & Security > Activation.
You will see a screen that looks like this:
It explains that Windows 10 in S mode only allows verified Windows Store apps to be installed. And that if you choose to switch to Windows 10 Pro (or Home, depending upon which version your laptop is eligible for) you risk malware and should download apps from trusted sources.
What you need to do is to click on the Go to Store button which will take you to the listing for Windows 10.
Be careful not to click the Go to Store button in the 'Upgrade your edition of Windows' however, as you will be charged for this.
You'll know if you've done it correctly because it should show a 'Switch out of S mode.' title and display Free instead of a price.
Click the Get button and then Install. You will see a warning to save your files, and once you click Yes, let's go, it will make the necessary changes which won't take long at all.
Can I go back to Windows 10 in S mode?
Microsoft says it's a one-way deal: once you switch out of S mode you cannot go back. But you can if you have a Surface device and are willing to put in some effort.
Head to Microsoft's website where you can download a recovery image for your laptop. You'll have to sign in with your Microsoft account to download the file.
The process will restore the laptop to factory settings, so all your files, settings and apps will be wiped, so be sure to back up anything you don't want to lose.
You need to put the image onto a suitably sized USB drive, which will wipe any files already on it. Follow the instructions on the website to create this 'recovery drive'.
In order to use it, make sure it's plugged into your Surface which must be switched off. Hold the volume down button and press the power button. Let go of the power button and only let go of the volume button when the Windows logo appears on screen.
This starts the recovery process. Choose Troubleshoot, then Recovery from the options and follow the instructions on screen. For more detail, see our guide to resetting Windows.