Wifi device is off, how do I turn it back on?

My new laptop was working fine until yesterday afternoon, when I discovered that it had lost its connection to my wireless network. Delving into the settings informed me that the Aspire E1-571 had no wireless device. Nothing I did disabused it of this erroneous notion, so I returned Windows (8) to its default settings.
That improved the situation slightly, device manager show the wireless device, however the toggle next to it is in the OFF position and it's greyed out. Fn + F3 toggles flight mode, but the wireless device remains off.
How do I turn it back on?