config.msi is a (hidden) subdir, usually created at the root of %SystemDrive% (eg. C:\Config.MSI) - here the installer creates backup copies of overwritten / removed files and/or settings during the installation, in order to be able to do a full rollback if the install is aborted (either by the user, or by some error)..
It could be that you have a hidden file at %SystemDrive%\Config.MSI, or that your systemdrive is full? (with a large install, a *lot* of .rb (rollback) files are created, and finally deleted).. Or just try creating the dir manually, and let the installer manage it (although it should create it all by itself...)
Also, there should be options (either by calling MSIEXEC manually, or perhaps by registry overrides) to NOT be able to do a rollback in case of a failed/aborted install, but that is generally not recommended...
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saybibi();
//john
#include <stddiscl.h>