About Windows 7 SP1 MUI Language Packs. MUI stands for Multilingual User Interface. There are full (100%) and partial (80% according to Microsoft) MUI language packs. Full languages change entire Windows 7 environment, partial languages lack some localization and the untranslated user interface is always in English, regardless of the original Windows 7 display language. I recently purchased a netbook on Amazon, and weirdly enough it came with Windows 7 Starter German. I want to change the language to English, but am having a lot of difficulty doing this. Smart Label Printer 440 Drivers Php Melody 1.8.1 more. here. If I understood correctly I need to install a new MUI, but can't find where to do this.