No sign of wifi

Hello, i updated my sony vaio e series to windows 7 ultimate a few days back
from then , my laptop cannot recognise wifi signals
1.i downloaded all drivers, the bluetooth works
2.the wirless switch is on
3.i checked the device drivers, all the network adapters are upto date
but the PCI device has an exclamation mark on it
4.the services are running
5.in network connections,adapters are enabled but there is a cross on all wireless adapters....

i tried everything , i am worried