Toggle Airplane Mode...
BUT, if this gets turned to "ON" when you NEED a connection... well, obviously, that's a problem. It's a strange feature to even see in Windows 10 when the device you're on is a desktop computer but because it is apart of the standard operating system, it is built-in to every device.
Here's how to turn it "OFF" (or toggle it "ON" if you need that for some reason; the process is the same...)
1) Find the "Action Center" Icon
It looks like the image below, in the bottom, right-hand corner of the screen--the system tray.