display menus and dialogs in the targeted language, only a localized version uses translated file and folder names. [what does this mean? some special folders are localizable (Documents, Downloads, ...) but a user created file/folder is not localizable (by the OS). Doesn't a language pack localize the special folder names? What else could it do?] A localized version of Windows translates the base operating system, as well as all included programs [what programs?], including file and folder names [so it does localize file/folder names. this contradicts above], objects names [what's an object?], strings in registry [really? what strings?], and any other internal strings used by Windows into a particular language. Localized versions of Windows support upgrading from a previous localized version and user interface resources are completely localized, which is not the case for MUI versions of a product. [what is not the case for MUI?] A MUI version does not contain translated administrative functions such as registry entries [registry entries are functions?] and items in Microsoft Management Console. One advantage of a MUI version is that each user of a computer can use a different language. For a localized version of the OS, this is not possible. It may be possible for localized applications but requires installing multiple versions; one for each language, and this may lead to application storage space and side-by-side installation issues. With MUI, the single version supports multiple languages, and the OS and applications use the user's preferred language. Further, the same OS can host an application that uses any of the application's supported languages which may be different than the OS selected language and even a language that's not supported by the OS. History MUI was introduced with Windows 2000 and is supported in each subsequent Windows release. Windows 2000 and Windows XP MUI products for these versions were available only through volume agreements from Microsoft. They were not available through retail channels. However, some OEMs distributed the product. Languages in Windows XP Up to Windows XP, MUI packs for a product are applied on top of an English version to provide a localized user experience. There are a total of 5 sets of MUI packs. Set 1 German French Japanese Korean Chinese (Simplified) Chinese (Traditional) Set 2 Arabic Hebrew Spanish Italian Swedish Dutch Portuguese (Brazil) Set 3 Norwegian Danish Finnish Russian Czech Set 4 Polish Hungarian Portuguese (Portugal) Turkish Greek Set 5 Bulgarian