I erased Windows 7 and installed Ubuntu 12.04 on my Dell Latitude E4200.

I an very happy with my choice but with little pity.

I cannot use the wireless service in my university as the build-in device works unstable. I bought a USB wireless device, which solve the problem.

However, the build-in device keep to sent me message about unable to connect, which waste laptop's cup & battery.

The phsical bottom to turn off wireless affect both devices.

So the question is: "How can I manually shut down wireless device?"

There is another interest comes to my mind: "Does 2 wireless improve the overall internet usage if I run a high-internet-consuming program like BT ?"

Thank for your time and energy.