When you are installing Rumba in any configuration using the Setup wizard, the installation process can completely roll back. That is, it undoes every operation that it performs during an installation, modification, repair, or removal. This is particularly helpful if you encounter a fatal error during an installer session. The computer can return to the precise state it was in before the installer session. This includes restoration of deleted or overwritten files, registry keys, and other resources.
Roll-back disk space requirements
The disk space for installing a specific feature can be twice the size of the net disk space consumption. Files that are deleted or overwritten during the course of an installation or removal are temporarily saved to a backup location so that they can be restored if necessary. After a successful installation, or installer operation, all temporary backup files are deleted.