mariner,
thanks so much for all your time and valuable info. that apartment building example made it very clear. (you should write for the “for dummies” series – you’re good at explaining things to a layman). In general I am fairly proficient with computers and have helped neighbors/relatives/friends with their issues, but when it comes to networking I have a mental block it seems. I am completely clueless.
I’ll get the router, a new modem and spybot, and then hopefully the computer will live happily ever after. thanks again!