http://www.winsupersite.com/win7/oem.asp One of the more mysterious ways in which you can legally acquire Windows 7 is through the so-called OEM Packaging. OEM stands for Original Equipment Manufacturer, which you can generally think of this term as meaning "PC maker" or, more precisely in this case, builder ." And given this, you may assume then that Windows 7 OEM packaging is thus off limits to you as an individual. This is mostly correct, as it turns out. Previous to Windows 7, Microsoft actually did allow individuals to purchase OEM versions of Windows, but only if they intended to install it on a brand-new PC that they were building. As Ed Bott pointed out in a 2008 blog post, the previous end user license agreement (EULA) for OEM Windows versions specified the following: OEM system builder software packs are intended for PC and server manufacturers or assemblers ONLY. They are not intended for distribution to end users. Unless the end user is actually assembling his/her own PC, in which case, that end user is considered a system builder as well.