LMJ-
If you don't have the router manual, you can access the user interface by:
-go into command prompt (Start< Run< type "cmd" without the quotes and hit [ENTER])
-type "ipconfig" without the quotes, hit [ENTER]
-copy the numbers reported next to DEFAULT GATEWAY into your web browser's URL
-when prompted for a password, try any combination of these, depending on the brand of your router:
User: admin
password: password
User: admin
password: (blank)
User: (blank)
password: (admin)
User: (blank)
password: password