The .NET Framework 2.0 Japanese language pack is now available for download.  This page has more information about the language pack (the text is in Japanese) and you can download the language pack setup package from this location.

I would also like to provide some helpful information about the setup package for the .NET Framework 2.0 Japanese language pack if you will be installing it as a part of your setup package:

Silent install command line parameters

The command line to silently install the .NET Framework 2.0 langauge packs is slightly different than it was in the .NET Framework 1.1.  Here is the command line syntax you should use to silently install the 2.0 language packs:

langpack.exe /q:a /c:"install.exe /q"

Note that the same command line parameters that I documented for the .NET Framework 2.0 apply here, because the same setup wrapper is used for the language packs as for the core redistributable package.

This command line will be the same for all additional .NET Framework 2.0 language packs when they are released.

Detecting whether or not the language pack is installed

You should use the following registry key/value to determine whether or not the .NET Framework 2.0 Japanese language pack is installed:

• Registry root: HKEY_LOCAL_MACHINE
• Key name: Software\Microsoft\NET Framework Setup\NDP\v2.0.50727\1041
• Value name: Install
• Value data type: REG_DWORD
• Value data: 1

You can also use the same set of return codes that I documented for the .NET Framework 2.0 to determine success or failure of language pack installation, because the same setup wrapper is used for the language packs as for the core redistributable package.

When the remaining .NET Framework 2.0 language packs are released, the detection method will be the same except the key name listed above will be the 4-digit language code corresponding to the language in question instead of 1041 (which is the language code for Japanese).

Should I install the Japanese language pack with my Japanese .NET Framework application?

The general answer to this is "yes."  The .NET Framework 2.0 is separated into a core and multiple language packs, and the common-language runtime (CLR) is MUI-aware.  That means that the CLR will use the OS language preferences to determine what strings to load when running managed applications.  If the language pack for the preferred language is not installed on the system, the CLR will fall back to the English string resources installed as part of the core .NET Framework 2.0 redistributable package.

The .NET Framework 2.0 language packs provide localized string resources for the following:

• Exceptions thrown by .NET Framework class libraries that are not caught by the calling application
• Compiler messages from managed code compilers (such as csc.exe and vbc.exe)
• Usage information for managed code tools that ship as part of the .NET Framework redistributable (such as caspol.exe)