re ipconfig are you opening a command prompt first? i.e. Start - RUN - type 'cmd', then 'ipconfig /all'?
Re the modem, if it is the same I saw yesterday at a client's, you should have two lights on the right hand side of the modem - one with a picture of a telephone, one with a picture of a planet (our's presumably!).
Are the lights green and steady?
The telephone one relates to the ADSL connection - i.e physical connection to the socketm the other one would tell if you're connected to the outside world.
amofw