For the people who has widescreen monitors (LCD).
You can do this to change the game resolution to 1600x1200.
What you need to do is:
1 - Click Start, then Run.
2 - Type in "regedit" (without "")
3 - Go to HKEY_CURRENT_USER / Software / Webzen / Mu / Config
4 - There should be a file that says Resolution double click it
5 - There should be a Hexadecimal value of 1, 2, or 3 (1 is 640x480, 2 is 800x600, 3 is 1024,768) change it to 4 (1600x1200)
Now, there isn't actually added the 1600x1200 to options on launchers because it haves a problem with the fonts size because the can't be read due to it's small size.
But with
This Guide you can fix this and play in a 1600x1200 resolution.