[Solved] i was lucky enough we had two spare laptops of the same brand, dell latitude E6420, so what i did was i replaced wireless adapter and connected with another computer,after that test it was still not working, then after that i become sure that the problem is hardware, it's not related to OS, or driver, i have already done all these tests for almost 3 days, i searched lots of forums, i believe you also need to do some tests, until you'll be sure that you're last chance is to test hardware, that would surely be replacement for your wireless adapter........... best regards, Sanaan Barzinji Erbil, Iraq