hey, seems you might have a mac address problem...
this can be fixed by going into network connections.
right click on your connection, then click the box
"configure" which should be next to the connect using "your devices name"
then in the new window click the tab advanced, then click network address, you probably have it set to not present or FF FF FF FF FF FF?
you need to change the mac address, so seek another pc and find it by typing ipconfig in dos prompt, find it and type it exactly, but change the last digit, it might say 01, change it to 02 or somthing different.
i hope this helps as i fixed one at work that had a similair problem, only it was after windows sp2 had installed on a machine. im clueless to how it causes problems? probably cause its microsoft :)) hehehee
good luck