I bought an OEM of Vista back in the day and installed it on a system, then a few months later I got a new system. I used the same copy (and DID retire the old one, recycled parts for the new one) and the new system would not activate. But I just called the Microsoft number that they give you when it fails, I got a number to type in and then my new system was activated. So, even though you probably aren't supposed to shift motherboards with an OEM copy, in reality you can.
I cooked a BIOS and had to replace a mobo. There was an OEM copy of XP Media Center installed.
Upon replacing the board, and firing up the machine, I received this message, "the BIOS update was not successful". No s***, I muttered to myself ,as Windows then told me I had 3 days to reactivate.
At any rate, Windows assigns points to hardware, and measures those points against time. Replace too many points, in too short a time, and it deactivates. As you might suspect, a motherboard is a lot of points, but so is the LAN card. Since they both go when you change the board, it makes sense that the current activation would fail.
But, it also debunks the urban legend, that you can't change the board with an OEM copy of Windows.
It has to be said, very much in M$'s favor, that they hold to a very liberal interpretation of their own builder's license, which is very much in our favor.
Early manufacturer installed OEM XP copies, such as the copy in my 6 year old Emachine however, were held to a more stringent standard. I'm pretty sure that if the mobo decides to call it quits, then that copy of XP dies right along with it.
This mostly is because that the "copy of Windows", is in reality, only a disc image, plus the board BIOS is bound to it.
Raybay claims that later Emachine restore discs have been used to successfully install Windows to machines with different boards. He called this a "mistake". (Yet he apparently will do it nonetheless).
But I wouldn't be too surprised if at some point one of those fails some authentication thing.
