I’d suggest that you try…
If you are using Enternet 300, go to there delete your profile, don’t forget your password and ID. Delete your current profile then click on ‘create new profile’ from scratch. Very easy.
If that fails, make sure that your connections are good between the pc and the phone line and the router box.
If that fails, call Hinet. And ask for networking help. They may have someone who speaks English!
If that fails… Uninstall the Enternet 300 software and reboot. Then reinstall that.
If that fails… take your pc to an engineer and have them reinstall the networking drivers for you, reboot, then install the Enternet 300 software again. Try it out, too.
If that fails, pray to god.