conv_all.exe requires the Microsoft .NET Framework 4 which is part of Windows 8 or newer, or which can be downloaded from https://www.microsoft.com/en-us/download/details.aspx?id=17718. And the Microsoft .NET Framework 4 Full Language Pack can be downloaded from https://www.microsoft.com/de-de/download/details.aspx?id=3324.
This command converts the named files. The convertion is done by repeatedly invoking the batch file conv_all.bat which converts a single file.
The file conv_all.ini must be located in the same folder as conv_all.exe. It is an INI file with following keys into the section Settings: