I do not know if Gandalf gave you the soloution, but to get your Router IP, you just need to go on "Start meny" and then "Drive" ore what it stands in English Pc's and then you just write cmd there, and in CMD you write ipconfig, then you look at Standard gateway : There is an IP, mine is 192.168.1.254 (I use Jensen Scandinavia) and then you just open the IE, ore FF if you use that, and write that in. It will come "Username and Password", it will be admin, if no one in your house have set a password on it! Then you just have to write admin in username, and leave password empty.
I don't know if this was your problem, but good luck! =)