No internet ID. Problems with one PPP message

The last Thursday my computer and inernet worked perfectly, next morning when I started suddenly the computer paralized so I had to restart manualy, but since then I could not connect to internet.

I had already checked with my internet provider and is not a matter of signal, the modem or the cable, I do not know if the 2 ethernet ports can breakdown at the same time, also I tried to connect using a PC-USB cable, but I could not.

I tried to reconfigure my internet following the steps on this post: Connecting to the Internet via cable, DSL, or local area network (LAN) in Mac OS X v10.5 or earlier, but my computer do not detect neither my ethernet cable nor my usb-PC cable. When I select any conection option no internet ID appears.

Can it be a software problem or is it a hardware issue?

The Assistance shows me a message that I have problems with one PPP, I do not know what does it mean.