Network cable unplugged?

[Joe]

So the internet connection won't work now. Apparently
the internet just stopped working and the Network Cable
Unplugged bubble came up, and has been like that for 2
days. As far as I know, no modifications were made to
the computer, and everything is plugged in right. I have
2 computers, mine is connected through the homeportal
router thing. And my moms computer is connected to the
network using a Phoneline adapter. Any ideas on how to
fix this?