I had this problem last year and eventually found the answer to my problem. Don't know if it will help you, but this was the solution for me..
Sucess..A thread in Helproom gave me a clue. I checked the DCHP client in msc services and guess what,..it was Disable ! Set it to Auto and i was able to set up the router, which I am now using..Thanks to all for your response.
Go into MSCONFIG and look at services. see if there is something called DCHP client. This should be enabled as Auto.
Hope this might help.