By "not loading", do you mean it continuously "loads" but never finishes? or does it show some kind of error? or it shows you the "Old Browser detected" [ B.S. >:! ] webpage ?
What browser are you using? Try deleting its cache; if that fails, unplug the router from the wall, AND the DSL cable. Wait a couple of seconds (10 in mine), and then plug it back in. Plug the DSL cable, and then try to connect from your MacBook/Your Parent's computers (do this step by step so the router configures itself properly).
[EDIT:] Before going wireless, try a wired connection first[/EDIT]
If all that fails, call Comcast, I'd say (be aware that they *do not support Mac browsers* so ask them about your parent's computer (hopefully they're using PC [never thought I'd say that again in my life xD] )
ex. Are you using a Static IP ?