Right click on the Start menu (Windows Icon) and go to Control Panel. Change the View By in the upper right hand corner to small or large icons. Then click on Network and Sharing Center:
In the menu on the left click on Change adapter settings.
You should see your Wi-Fi adapter listed and it should say Disabled. Right click on it and go to Enable. You will be prompted for admin credentials. Use the following:
Username: .\administrator                          (do not forget the .\ before administrator)