networking - Wifi not working after updating ubuntu to 14.04 - Ask Ubuntu

solved: turned out problem secure boot, refer solution here "why "required key not available" when install 3rd party kernel modules or after kernel upgrade?"

i got dell inspiration 15 , had ubuntu installed on default, updated running following:

sudo apt-get update && sudo apt-get upgrade sudo apt-get dist-upgrade 

it ran fine, finished updating on wifi , asked me restart, after reset, wifi not working , not showing in ifconfig or anywhere.

the output of :

lspci -nn | grep 280 lsusb rfkill list   batee5a@bat335a:~$ lspci -nn | grep 0280 02:00.0 network controller [0280]: intel corporation wireless 3160 [8086:08b3] (rev 83) batee5a@bat335a:~$ lsusb bus 002 device 001: id 1d6b:0003 linux foundation 3.0 root hub bus 001 device 004: id 8087:07dc intel corp.  bus 001 device 003: id 0bda:0129 realtek semiconductor corp. rts5129 card reader controller bus 001 device 002: id 1bcf:2b90 sunplus innovation technology inc.  bus 001 device 001: id 1d6b:0002 linux foundation 2.0 root hub batee5a@bat335a:~$ rfkill list 0: hci0: bluetooth     soft blocked: no     hard blocked: no 

i've tried solutions in other threads , non worked thats why i'm posting here new thread, please?

edit: further results of codes.

batee5a@bat335a:~$ sudo modprobe iwlwifi modprobe: error: not insert 'iwlwifi': required key not available batee5a@bat335a:~$ dmesg | grep iwl batee5a@bat335a:~$