Try and make head or tail of Microsoft's policy shift on the definition of a system builder. It used to be effectively "a builder of a system" but it appears now to be, depending upon where you read on their huge corporate site something akin to " a builder of a system for sale onto a third party". So if you build a system for your own use then it could be construed that you are not a sytem builder! If so, then to install this software on a PC that you have built for your own use appears to be technically illegal, but if you sell the machine to a 3rd party then it isn't. So that's cleared up that! The packaging also states that the preinstallation OPK package needs to be downloaded before installing Windows 7. Having read other reviews elsewhere it appears that this is not necessary and was certainly my experience.
So, Windows 7 64-bit itself. There are so many reviews on the product itself, I won't add to the debate other than to say that when installed on an SSD drive, boot-up time from start to user account logon (including the system pause for BIOS entry option) is around 15-20 seconds. Following user account logon being entered, it takes around another 15 seconds to load and use. All in all, very pleased with Windows 7 and a vast improvemnt over Vista.