Grumbling about a houseful of computers that don't speak to one another

PROBLEM: I'm perpetually annoyed that my computers won't file-share. McAfee "tells" me they are competing for network loyalties, but WTF — I only have one wireless network (operated by Roadrunner, no router needed). Do I need to dump McAfee? I am also mildly obsessed with back-ups, as if the world would end if all my precious files disappeared. What are my resources for storing critical files online? So I draw little schematics.

SOLUTION OF THE MOMENT: I signed up for a Box.net account (1 gb...