*Usually encountered on new, store bought, machines*
If you unable to install any programs, and are prompted to only install programs from the windows store, or are unable connect external devices (such as printers) there's a good chance it's in default 'S-mode'.
To remove (per MS's website):
1, Right click on Windows button (4 squares on the toolbar on the bottom)
2. Go to Settings.
3. Then select Update & Security.
4. In the left sidebar, click Activation.
5. Then click “Go to the Store.” You will see this under the “Switch to Windows 10 Home / Pro” section.
6. Press the “Get” button under the “Switch out of S Mode” section and wait for the process to complete.