Local Language Versions in SQL Server
SQL Server supports all languages that are supported by Windows operating systems.
Cross-Language Support
The English-language version of SQL Server is supported on all localized versions of operating systems.
Localized versions of SQL Server are supported on localized operating systems with the corresponding language or on English-language versions of supported operating systems by using the Windows Multilingual User Interface Pack (MUI) settings. For more information, see How to: Change Operating System Settings to Support Localized Versions.
Localized versions of SQL Server can only be upgraded to localized versions of the same language, and cannot be upgraded to the English-language version.
Localized versions of SQL Server can also be installed side by side with English-language instances of SQL Server.