Hi Jeffrey,
I would suggest you to remove the Korean language from the computer, add it again and check if that resolves the issue. You may follow these steps:
a) Press “Windows Logo” + “X” keys on the keyboard and select “Control Panel” from that menu.
b) Select either of the options: “Small icons” or “Large icons” on the “View by” menu in the upper-right corner of the Control Panel window.
c) Click on “Language”.
d) On the “Language” window, click on the Korean language that you have added to the computer and then click on the option “Remove”.
e) Now, click on “Add a language”.
f) In the “Add Languages” window, search for the Korean language and then double click on it.
g) The Korean language is now added to the computer and you should be able to see this entry in the language list.
h) Now, try switch the keyboard layout to Korean Language by pressing the “Windows Logo” + “SPACE” keys on the keyboard.
i) Open a text editor eg: Notepad or WordPad and then check if you are able to type in Korean Language.
Hope this is helpful. Please get back to us with the result.