First thing to try is check the firewall settings.If one browser is working but the others aren't, as said above, that's the likely culprit.
However, your post suggests that you're no stranger to browser crashes (which should be a bit unusual) so maybe your system is a bit borked and does need re-installing.
Dial up is what we used b4 cable. In the connection options in any browser, it should appear as an option, but if you're on cable, it shouldn't be the default.
You need to back up any files/pics/downloaded programs etc that aren't part of the OS before formatting (to a second hard drive, external hard drive, or a dvd disk),and check they work from that medium.
And you'll need the OS installation disk, of course.