Helping a friend with their HP Pavilion DV3500 laptop. The wireless light was glowing amber (meaning it was disabled) but pressing the button did nothing. Turns out that the wireless can be disabled from software and the button then becomes useless.
Searched for, downloaded, and installed the "HP Wireless Assistant" (current version is sp49018 v3.50.12.1). As soon as it came up it offered to enable the wireless, which it did, and now the indicator light is blue and all is well.