I am unable to switch the wireless device on?

My laptop crashed and I re-installed window vista on with
the supplied recovery disc. On re-booting, I found I could
not connect wirelessly to the internet because operating
the small 'radio' button would not make the wireless device
light turn on. Looking in the BIOS it informed me that the
'Default Wireless Device' was disabled. The only other
option was 'Last State' but that did not solve the problem either. Does anyone have any ideas for a
solution to the problem.
Medion laptop, MD92690 Model No WIM 2160 notebook