I have a computer issue that is quite puzzling to me, and I wonder if anyone knows what is going on?

Recently I networked my two computers to be able to share files. Shortly after that, I started to get a pop up to connect via dial-up. I am running DSL and both machines are linked to the same router. My DSL is on full-time so signing up with dial-up is irrelevant. I assumed it was because my wife’s computer is hooked first into the DSL router, or that mine is farther away. I pulled up a window in my network connections (in Settings, Control Panel) and unchecked a few boxes, which solved the problem to the extent that now the only window that pops up now has the heading Network Connections, with the typical yellow triangle with an exclamation point in the center. Underneath it reads Cannot connect the phonebook entry. Error 720: A connection to the remote computer could not be established. You might need to change the network settings for this connection. For further assistance, click More Info or search Help and Support Center for this error number.

None of those Help links exist in this persistent pop-up window, and this problem doesn’t hurt anything, other than being annoying while I am online. I did look for Error 720 online, and couldn’t find it. I’d appreciate some advice on this.