[Resolved]
Fortunately, I have stored the settings of my bbPress in my laptop. I uploaded again in the former path. I reloaded the former site, and it worked. Then I changed the path, and tested whether it works in their new path. It worked! I deleted the old folder, and I have no problem in my root directory.
The service guy in my hosting company has had hard time, ad the setting was not in Enlgish. I still wonder what makes it work in Korean language even after I have delelted all the non-English related settings, files and folders.
I have deleted my files in the old URL. So I can get access to phpmyadmin or reinstall. My account says it has already been installed.
My attempt to be serviced by hostgator failed, as they can’t read Korean language. So I tried to disable the local language options. I deleted the ko_KR in bb-config and also deleted .mo and .po file in language folder. The old setting seems to be working with the Korean language. How can I disable the Korean language and return to English mode to be able to be serviced by my host?