What is Windows 10 in S Mode?
Microsoft’s Answer to Chromebooks
Some Windows 10 PCs, including Microsoft’s Surface Laptop, come with “Windows 10 in S Mode.” PCs in S Mode can only install applications from the Microsoft Store. But you’re free to leave S Mode if you like.
Windows 10 in S Mode is a more limited, locked-down Windows operating system. In S Mode, you can only install apps from the Store, and you can only browse the web with Microsoft Edge.