To purchase OEM System Builder software, you must be a System Builder and accept the System Builder License. "System Builder" means an original equipment manufacturer, an assembler, a Refurbisher, or a software preinstaller that sells the Customer System(s) to a third-party. OEM software may ONLY be distributed with a fully assembled computer system. For a desktop operating system or application software, the software also must be preinstalled on the hard drive of the fully assembled computer system, using the OEM Preinstallation Kit (OPK). The system builder who installs the software is responsible for the provision of end-user support.