I recently installed Ubuntu 12.04 on my Dell Inspiron 15 7537. It was working fine but after installing some updates (Not sure which ones) I rebooted and could no longer connect to wi-fi. It's a dual boot with Windows 8.1 and wi-fi works fine for that and Ubuntu does let me connect using a wired connection.

After reinstalling it's still giving me the issue which makes me think it's a hardware fault but the fact it works in Windows is making me doubt that.

One thing worth noting is that when I start Ubuntu it displays the following:

iwlwifi 0000:02:00.0z request for firmware file 'iwlwifi-7200-7.ucode' failed

iwlwifi 0000:02:00.0z no suitable firmware found!

Any help would be much appreciated.