First make sure you have an ethernet cable plugged into your laptop or PC that is connected to either your modem, router, or gateway device.
Locate your wifi connection in your system tray as shown below.
You will either see the little radar or bars indicating that you are on a wifi connection vs ethernet connection.
Right click that little icon (sometimes you will find this in your hidden icons by clicking the up arrow in your system tray).
Select "Open Network and Sharing Center" as shown below.
Click on “Change Adapter Options” or "Change adapter settings".
Locate your wifi adapter (hint: it will be the only one with green bars that looks like your cell phone's signal strength)
Once located, right click it and select "disable"
You are now officially on your hardwire connection. To enable it again after work you may follow these same steps and choose enable. Just be sure that if you do, you remember to disable it again prior to starting your work day.