If you're using bcm43xx, you need to install firmware. See here: https://wiki.ubuntu.com/WifiDocs/Driver/bcm43xx?highlight=%28bcm43xx%29 #head-cf3f0ec9146ae9441b39c4bed74e5d044ef78d2f for the really simple method. -- bcm43xx not working on HPzv5404us with BCM4306 (rev 03) https://launchpad.net/bugs/48347