Wireless Network Issue on Fujitsu Siemens

I have a Fujitsu Siemens AMILO and it used to pick wireless network with no problem on Windows Vista, all I had to do is to press Fn and F1 simultaneously and the message in the attached picture would appear. So I switched WLAN on and it would work, ever since I installed Windows 7 the wireless stopped working. It doesn't display any error message, I am still able to connect using the USB modem but pressing the short buttons for wireless are no longer activating it .
Any idea how to fix this issue?
