Agreed. Norton Internet Security causes problems for a lot of people. Just today someone called me and took us 2 hours to figure out that Norton Internet Security was blocking access. (He told me he had Norton at the end of the two hours lol.) Uninstalled that and the internet came back.

Also when you map the network drives, instead of using \\MainComputer\Amazing Charts; try \\192.168.2.120\Amazing Charts if you already haven't.