When ever i connect to a wireless after sometime it says your network settings does not match the requirements?

when ever i connect to a wireless after sometime it says your network settings does not match the requirements of this network and thn i cant connect to tht network anymore... sometimes it evn says tht .. the capability of ur network adapter does nt match wid da network ..nd den they place a cross beside it .. there were six networkz unsecure nd all of them got a cross..can anyone tell how to deal with this problem ? i'll be really thnxful =)