Wireless capabilities turned off

Hi, 

I am using DELL E6420, Windows 7 OS. 

I am facing problem with wireless capabilities turning off automatically. Earlier also i reported the same. Still it is not working. Able to connect to device using USB, not able to USB for data (From Phone/Dongle). 

I have updated the all the network related drivers. 

Please help me to rectify the issue. 

Thanks,

Jegan