Hi U can fix it by open the Settings App (gear icon on your Start Menu): Go to System - About. And look for exactly the propblem what is the exact edition of system? Or is that Windows 10 S?
If so, that needs to be switched out of S mode: Open the Settings App ==> Go to Update and Security - Activation
In the Switch to Windows 10 Home or Switch to Windows 10 Pro section, select Go to the Store. (If you also see an "Upgrade your edition of Windows" section, be careful not to click the "Go to the Store" link that appears there.)
On the Switch out of S mode (or similar) page that appears in the Microsoft Store, select driving directions the Get button.
After you see a confirmation message on the page, you'll be able to install apps from outside of the Microsoft Store. Hope that it useful with you.
