Dell studio 1555 Wireless adapter Problem

Hello All..! I've Studio 1555 with Factory default Windows Vista, I am using connectify software for internet sharing to other laptops, but from few days, it is not working...I reinstalled it again,Updated my wifi drivers from vendor's site, even restored my windows to earlier restore point, also I set up my own windows ad-hoc network, but this ad-hoc created network or the connectify created network, both are not found on nearby laptop's network search..my wifi adapter stopped broadcasting..although I can connect to ad-hoc or some other network.

please help..