MLC files exist as 2 different types. Please find information about each of them below.
Type 1: Microsoft Language Interface Pack
Files with mlc file extension are language interface packs for Microsoft Windows operating system. They change language in wizards, menus, etc. These files are probably not meant to be accessed by use...
Files with mlc file extension are language interface packs for Microsoft Windows operating system. They change language in wizards, menus, etc. These files are probably not meant to be accessed by users. They probably cannot be converted to anything else.
Microsoft Language Interface Packs (LIPs) require installation of a basic language. This basic language is the source used to translate the user interface. LIPs often only translate one part of the user interface. These LIPs must be used by the system they support. For example, Windows Vista LIPs cannot be used on Windows 7.
When installing a new LIP or copying a LIP to another Windows machine, the mlc files must be renamed. This requires changing the file extension to cab instead of mlc.
The mlc file contains the language pack. Mlc files are binary format. They are meant for system use rather than user access. The default software to open mlc files is Microsoft Windows 10.