1.  Press the Start button located at the bottom left of your screen.

2.  Select the Settings icon, located just above the power icon on the Start menu.

3.  Select Update & Security in the Settings app.

4. Select Activation, and then select Go to Store.

5. Select the Get option.

6.  Then hit Install when ready to proceed.

7. The process to switch out of S mode is seconds (maybe about five to be exact). You do not need to restart the PC for it to take effect. You can just continue on and start installing .exe apps now in addition to apps from the Microsoft Store.

And that's it. While Windows 10 in S mode is built for security and performance it's not for everyone. Microsoft at least gives you the choice as to which version you prefer.