Normally when your laptop or desktop (with wireless in-built) is connected to a wireless connection and you connect a wired Internet connection, the network usage will still be from wireless connection. There might be instances where you want to be connected to wireless connection but want to use the Internet from a wired connection.
You can make Windows use the wired connection instead of automatically using the wireless connection. To do this, open the Network Connections in Control Panel-> All Control Panel Items-> Network Connections. You can also access it using the command ncpa.cpl in the run command (Win+R). From the file menu, select Advanced-> Advanced Settings.
In the advanced settings tab, you can see all the connections listed. The network connections are accessed in this priority. So in case you want to use the wired connection, you need to make Ethernet to the top of the list.
Click OK when you are done. Now your computer will use the wired connection as default.