I have DSL with a Actiontec GT701-WG DSL Modem hooked to a Linksys 5 port switch. My wife has reciently set up a home office and shares one of the ports.

My question is, I believe her company has accessed my modem. I think they changed setting as I had to restart my computer to get a connection after they were messing with her system. They spy on her desktop but I don't want them to be able to see my computer or my web-log. If I change the password to my modem, does that limit what they can do to her computer? What can I do so they have access to her computer but not to mine?