LanguageMUI
MultiLanguage Windows resource data
File type: Settings, options, themes or skins file, System file
Files with mui extension are mainly related to Microsoft Windows are used for language packages with which you can add the default localization of your OS.
Found 4 different file type records with the same mui filename suffix.
What is mui file?
File type category:
Settings, options, themes or skins file
System file
Date updated: June 27, 2025
File extension mui is used for multi-language resource files used in Microsoft Windows operating system.
Various .mui files contain individual language resources used by multi-language editions of Windows 2000/XP and they are still used in other versions of Microsoft Windows.
The main purpose of MUI files is to support multiple languages. Instead of creating a separate version of the operating system for each language, Microsoft creates one version and then uses MUI files to translate the user interface into different languages. For example, if you change the language of your Windows operating system, it will load a different MUI file to display the user interface in the selected language. These files are usually located in a folder named "MUI" within the Windows directory on your computer. They should not be manually altered or deleted, as this could cause problems with the operation of the Windows operating system.
How to open mui file?
These *.mui files can be installed to Windows with the language options in Control Panels.
How to convert mui file?
There is no way how to convert *.mui files to other formats.
Suggested software to open mui file:
Associated software actions with the mui file
Software apps that manage settings for mui files:
Microsoft Windows (Microsoft Windows)
Microsoft Windows 10 (Microsoft Windows)
Microsoft Windows 8 (Microsoft Windows)
Microsoft Windows 7 (Microsoft Windows)
Microsoft Windows Vista (Microsoft Windows)
Microsoft Windows XP Professional (Microsoft Windows)
Microsoft Windows XP Media Center Edition (Microsoft Windows)
Microsoft Windows 2000 (Microsoft Windows)
Amiga MUI default class/library data
File type category:
System file
Date updated: May 15, 2018
The mui file extension is also related to MUI-Magic, a program for Amiga platform. MUI is an object oriented system to create and maintain graphical user interfaces.
The mui file contains class/library used for the program.
How to open mui file?
Probably not meant to be accessed by the user.
How to convert mui file?
Probably cannot be converted to anything else.
Suggested software to open mui file:
Associated software actions with the mui file
Software applications that handle other tasks involving mui files:
MUI-Magic User Interface (Other operating systems or devices)
Harmony Assistant instrument data
File type category:
Audio and sound file
Date updated: October 12, 2016
The mui file extension is associated with the Harmony Assistant, a music composing program for Microsoft Windows, macOS (OS X) and Linux operating systems.
The mui file stores instrument data from Harmony Assistant.
How to open mui file?
Use Harmony Assistant to open *.mui files.
How to convert mui file?
Harmony Assistant is able to export *.mui files to other formats.
Suggested software to open mui file:
Associated software actions with the mui file
Software applications that can open mui files:
Harmony Assistant (Multiplatform)
Software apps that create mui files:
Harmony Assistant (Multiplatform)
OpenGL Glut data
File type category:
Various data file
Date updated: August 7, 2018
The mui file extension is associated with GLUT, a tool that makes it considerably easier to learn about and explore OpenGL programming, developed by OpenGL.org.
MUI format is probably used for one of the resource files used by the program.
How to open mui file?
Probably not meant to be accessed by the user.
How to convert mui file?
Probably cannot be converted to anything else.
Suggested software to open mui file:
Associated software actions with the mui file
Software applications that handle other tasks involving mui files:
GLUT (Microsoft Windows)