"A clean installation is one that is done in the absence of any interfering elements such as old versions of the computer program being installed or leftovers f

"A clean installation is one that is done in the absence of any interfering elements such as old versions of the computer program being installed or leftovers from a previous installation. In particular, the clean installation of an operating system is an installation in which the target disk partition is erased before installation. Since the interfering elements are absent, a clean installation may succeed where an unclean installation may fail or may take significantly longer."