This may sound like a dumb question but I have to ask anyway. If you own an OEM desktop COMPUTER like Gateway, Dell, Acer, whatever, and you want to upgrade the motherboard in it, are you allowed to install an OEM copy of Windows onto it, if you purchase a new copy?

With a new/different motherboard, it's pretty much a new-build, isn't it ?http://www.tomshardware.co.uk/forum/235074-34-attn-difference-vista-retail-license

Don't know if it applies to XP but I'm fairly certain it is the same for win7.

IE: the OEM license you already have is non-transferable. If you can get a "fresh" OEM disk then it will have a different key that is not yet tied to anything.

Strictly speaking, there are really several different kinds of Windows Disks. For windows XP, at least, there is:

You've got Full, Upgrade, OEM Branded, OEM unbranded

Full Retail: most EXPENSIVE, can be moved from machine to machine. (just MAKE sure you uninstall then reinstall, and re-activate. You may need to call Microsoft for re-activation)!!

Upgrade: Requires a previous Windows OS, such as Windows 98, NT4, or 95. Can only be moved from machine to machine as long as the previous OS you "tied" it to (I don't think it actually remembers, but it's a licensing thing) isn't used. For example, if you have a copy of Windows 98 and a copy of windows 95, and you want to install Windows XP from an upgrade disk, you can use either one of the disks to "validate" the install (to allow you to continue) but ti my understanding the XP upgrade is more an amendment to the EULA for the original OS- that is, you could now use either the windows 95 copy or the windows 98 copy, but you couldn't use both, because legally the upgrade is "using up" the copy of one of them you own. (you could install using the windows 98 disk, and then later use windows 98, and then "legally" you still are fine because you have a copy of the also-eligible windows 95).

OEM Branded. Comes installed with a new BC (Branded OEM). Functionally identical to unbranded OEM (excepting of course the preinstalled crap that comes with a branded install). Can only be installed on One machine, after that, even if you have a fire or a complete system failure and need t oget a new machine, you'll have to buy a new copy of windows, as well. Of course you cannot "move" the install either (which would be difficult anyway since most OEM branded installations are actually recovery disks)

OEM unbranded is pretty similar to OEM branded, except it isn't associated with a specific- well, brand.
thanks, I think I found what I was looking for... from here:

http://arstechnica.com/hardware/news/2007/01/8730.ars

Quote

OEM software is also tied to the motherboard it is first installed on. Unlike the retail versions of Windows which can be transferred to a new computer, OEM versions are not transferable. What about upgrading hardware? Microsoft says that anything is fair game, except the motherboard. Replacing the motherboard in a computer results in a "new personal computer," which the company considers to be SYNONYMOUS with a transfer. It's not permitted with an OEM edition of Windows