You can install .NET Framework 3.5 on a non-English machine by providing the following command line:
To install .NET Framework 3.5 with a corresponding Language package, then you will need ot do the following:
1) Download 3.5 web or full redist
a. If full redist then you will need to extract it using the following command
i. “dotnetfx35.exe /x:<path>”
b. If web bootstrapper then you will need to create the following directory, at the same directory level as where you downloaded the web bootstrapper
2) Download and copy the language package into the appropriate dotnetFX35 directory
a. i.e. if x86 then you would copy the language package into:
3) Execute the Web or full redist package. The download manager will automatically determine which OS language that you have and install the matching language package with the OS language.
Follow the steps above only for step 3, use the /LANG:<lang> switch from the command line.
The general guidance is to install the core .NET Framework with the /LANG:ENU switch and then install the desired language packages.