In versions up to and including MotionBuilder 2010, user data were in the bin\config directory of the MotionBuilder installation directory. The MotionBuilder installation directory is typically in C:\Program Files\Autodesk\MotionBuilder\.
You may want to access these files, for example, to customize layouts, keyboard shortcuts, and Python scripts.
In Windows Vista and later, only administrative users have permission to write to the Program Files directory. To enable non-administrative users to customize these files, MotionBuilder creates a copy of the files in \Users\[user]\AppData\Local\Autodesk\[MotionBuilder]. This structure is created not at install time, but the first time [user] runs MotionBuilder, if it is not already present.
At install time MotionBuilder creates a structure at [MotionBuilder]\bin\config but this is only used as a template to create the files in \Users\[user]\AppData. The files are not read by MotionBuilder.
If muliple users run MotionBuilder on a machine then there will be a \Users\[user]\AppData\Local\Autodesk\[MotionBuilder]\config for each one.
The default installation path for MotionBuilder is:
In this documentation, [MotionBuilder] refers to your MotionBuilder installation directory, wherever it may be.
Directories of interest to Python under the installation directory
Directories of interest to C++ developers under the installation directory