Here is some food for thought:
Quoted from MS System Builders
"If the motherboard is replaced because it is defective, you do NOT need to acquire a new operating system license for the PC. The replacement motherboard must be the same make/model or the same manufacturer?s replacement/equivalent."
A system builder it seems would determine what constitutes as a qualifying motherboard.
As I see it, the purchaser of a generic OEM XP version of XP becomes the system builder and can determine what hardware upgrade becomes a system that the OEM is the sole support by the OEM.
This pretty much leaves it open to the OEM system builder.
As the OEM system builder they can define what hardware was upgraded in compliance with the OEM EULA when prompted for activation.
This would also seem to satisfy Microsoft's requirement that the OEM assumes all support of the OS for the reduced price of the OEM license. I am sure that generic OEM versions are still priced higher than the big system builders pay for each OEM license.
Systems shipped with the big box (HP, Compaq, Dell, Toshiba, Sony, Gates, etc. ) OEM versions would need to upgrade hardware supported by the vendor and would be limited by their licensing restrictions.
Now that certainly makes it more clear doesn't it. It does for me.
I build computer and install an OEM Lic OS. I am the OEM Builder, If I replace a damaged MB as long as I approve it is my equivalent replacement then the license is fine and the EULA is satisfied. The only kicker is the original MB has to be damaged.
That is my take on it. I did this with a PC at home and called they said fine... so it is all good. MS is just too wishy washy. I know what the EULA says but the clarification in the system builders section contradicts parts of the EULA or as I take it expands the intent of the EULA. So this is how I read the MS Babbling: AS long as you are the OEM, The MB is defective, then YOU get to decide what is YOUR OEM replacement MB. Seems cut and dried to me.