how do i set a wired connection to my aspire 5535 laptop

Atm i have a wireless setup on my acer aspire 5535 and i want to set up a hard wire connection to see what speeds i will get from my isp. Im getting varying speeds with wireless but no where near the 30MB fibre optic they said, my super hub is only around 2 feet from my laptop and in the same room. The wired pc in the other room is hitting over 30mb everytime so i want to set the laptop wired to see if its just the fact that its the wireless connection giving me speeds around only 12-15 mb, and see if it can more or less match the other pc when wired. What the problem is that when i actually plug a ethernet cable in it still says wireless connection, doesnt the computer automatically pick up the wired connection, and auto swap? If someone can maybe explain what i need to do to set up a wired connection to test the speeds and then what to do if i want to go back to wireless. Thanks in advance if anyone can help