Many a times , we all face some issues with the Config.Msi and RBF files,
well the CONFIG.MSI folder is a hidden folder on the root drive of Windows, usually Drive C. This folder is used by the windows installer process during an installation of software.
It saves files with the extension of .RBS and .RBF.
These are Rollback Script Files used by the installer to uninstall recent changes if an install fails somewhere along the way (Checkpoint) .
The rollback script file (.rbs) is always stored in the Config.msi folder on the disk where the OS is installed.
The .rbf files are stored in the Config.msi folder located on the disk where the program that is being backed up currently resides.
It is normally misunderstood that the above is ONLY created during MS Office apps, however the above files are created whenever any scripted installation is carried out, and Windows Installer is a worker.
Hope this helps.