What you do is go to Network and Sharing Center and click on the change adapter settings link. From there, if you have the Desktop Experience installed, you might not have the menu bar running across the top. You need to hit the Alt button on your keyboard in order to get the menu bar to show up. From the Advanced menu option, click Advanced Settings.
What will load is a funky little window with your adapters in the top part, and the bindings associated with the adapters on the bottom. For our purposes, you can ignore the bottom part of the window. We are only concerned with the top part.
In the top part you see all of your network adapters. You will also notice two arrows on the right of the selection window. What you are seeing is the adapter connection priority. The highest priority is on the top, running to the lowest priority on the bottom.
All that you need to do to set an adapter with a higher priority is to highlight the adapter, and click the up arrow. That’s it. Simple solution to a difficult problem.