WAN miniported??? Help!

Hello,

I'm currently experiencing some difficultues with getting online.

I've had a colleague test the internet with his computer, it works fine.

But with mine, it doesn't. I've entered my username/password - Hit Connect and see "Connecting through Wan Miniport PPPOE.

Error: 678: The computer did not respond.

Interestingly I get the same error report regardless of whether the LAN cord is plugged into the computer not!
My firewall is off, so I'm not sure what the problem is.

It's not a hardware malfunction I doubt, as I use the internet regularly at work, sometimes wireless but mostly through cable. (LAN)

Please Help!