I am giving an exact answer to the question: if WWW connection fails, what does the error message **Wired network disconnected** mean? It means your mobo ethernet ports are toast --- buy and install a nic card for $20.
I had the problem, got no response from TH and dozens of pure blubbering BS "software" suggestions from a dozen other sites. Many folks have this issue and packs of byte-boyz want them to fyuck-around reconfiguring files ... gawdsakes UBUNTU-FORUM is the worst offender -- instead of admitting that all real problems (like all honest Welshmen) are hardware problems and fixed buying a hardware solution.
With an attitude like that it's no wonder you didn't get any help. As has already been said, there are many possible causes and if you didn't give those attempting to help you enough information or refused to follow instructions of course you're going to get conflicting suggestions. Heck, if you entered my shop with that attitude I'd send you packing pronto.
"Wired Network Disconnected": Nine-of-ten chances the problem is hardware. Nine-of-ten chances the hardware problem is toasted mobo-ethernet ports. Yet, 99-of-100 GOOGLED suggestions point to a software issue. That's not "conflicted" that's denial! Yes indeed an attitude adjustment is needed --- especially among the *nix cognoscenti.
Fortunately it was not your shop I entered for confirmation of my suspicion, and my repair-part purchases were made there.