The downsides to an OEM edition are that the license bans users from transferring the operating system from one PC to another, it comes sans support of any kind, and it can only be used for a so-called "clean" install, which requires that data and settings be restored from backups, and applications be reinstalled, after the operating system is on the drive. There's nothing to prevent an individual user, however, from buying and installing an OEM version of Windows on their PC.
OEM copies of Windows are traditionally cheaper because they're intended for small-scale system builders who install them on new custom-crafted PCs.
"You can always do a clean install if you're upgrading, so long as you're upgrading a machine that's already running genuine Windows XP or Windows Vista," she said in an instant today.Ī slightly less-expensive alternative to a "full" license of Windows 7 - and one that can be applied on a blank drive or on a new PC that the user has assembled, is a retail "OEM" edition.
"So an OEM + an upgrade gets you the upgraded version."Ī Microsoft spokeswoman today confirmed Ligman's account of when it's permissible to use upgrade media - which costs up to $100 less than the same version's "full" edition - to install Windows 7 on a blank drive. "An OEM license is a full license," Ligman wrote in a comment to this blog post, answering a user's question. On PCs purchased with Windows XP or Vista preinstalled by the computer maker - which slap an "OEM" license of Windows on the machine - users can install a Windows 7 upgrade edition on that system's blank hard drive, but on no other, Ligman added. "For you, since you have the previous version FULL Windows license and qualify for the Windows 7 Upgrade, you have the rights to do a 'clean' install." "There are many, many, many, many of you out there that already own Windows licenses that qualify for the Windows 7 Upgrade, so this is a non-issue for you," said Ligman. That, said Ligman, means users must either have a "full" retail license of Windows XP or Vista, or assuming the Windows 7 upgrade is applied to an existing PC, that the upgrade is done on that same machine, which has a so-called "OEM" license attached to it. After you upgrade, you may no longer use the software you upgraded from," the EULA states. "To use upgrade software, you must first be licensed for the software that is eligible for the upgrade. In order to use upgrade media to install Windows 7 on a blank hard drive, users must abide by the operating system's EULA, or end-user licensing agreement ( download PDF ). "'Technically possible' does not always mean legal," Ligman said. "They often forgot to mention a very basic, yet very important piece of information," said Ligman about Thurrott's blog post and the resulting reports by others.