[ShadowTD]

I thought modems were delivered pre-registered these days? Anyhoo, turn the cable modem off, disconnect from the router and connect directly to the pc. Give it a few minutes and then power the modem back on again. You can now either:

a) Run the supplied CD and it should find the connection
b) Navigate to the setup page which I can't remember off the top of my head but hopefully someone will remind us.

Basically, the modem needs to be registered. Until then it's on limited profile only and can only get to the registration server.