What the bat file does is make a script file and runs it to see if it gets a result, forcing the UAC to ask for permissions, onces it has permissions it then takes the file you dropped onto it and adds it to the registry.
So from the looks of it, it might be that the UAC isnt getting triggered so the bat file isnt getting permission to write to the registry. Have you tried having the bat file set to always run as administrator?
Shane