I've Ubuntu on a dual boot, and I primarily use Windows. I was having an issue where my machine would completely crash when I tried to log in with the GUI. So I figured that I could get an update from the command line to fix it, which fixed the crashing issue.

However, most of the way through this long update process, it started displaying lots of error messages before finishing up. I didn't know what any of them meant (and unfortunately don't have any images), but it finished up, and fixed that other issue, but now it fails to connect to any network, wired or not.

Viewing the network settings in the GUI, I see something like there's no network hardware detected or something like that. I would look now but I'm booted into Windows on the affected machine.

Edit: I saw a comment asking for my machine and version so I'll add those now: I'm on an HP Envy dv7 laptop, I believe a 2012 model though I've had trouble finding a serial number or anything (got it refurb before I knew anything at all whatsoever about computers) and it's running Ubuntu 14.04 dual booted with Windows 10.

Edit 2: sudo lshw -class network returned hardware specifications (addresses, manufacturers, etc.) arp -a returned nothing