oh, haha my bad.
To change that you goto:
start->control panel->regional and language options->advanced tab (called administrative in vista)
At the very top, it should say "Language for non-Unicode programs." Then just select korean from the drop down box(press change system locale in vista).
You're gonna need your Windows Vista CD... I used to have vista (waiting for more x64 program support and more vista support) and I think I did it the same way.