I can't get my router to work

I just moved and can't get my Belkin router F5D5230-4 to work with the computers at my new place. It works fine at my friend's house. I do not have a manual. Is there a way to make it work here at my new place or should I just get a new one since this model has been replaced by F5D5231-4. We have a Charter Cable connection which works fine. We just can't be online at the same time which is getting to be a pain. Any help is appreciated. Speak slowly and clearly - this techie stuff is new to me. Thanks - Ross