Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I have used XP and Vista OEM installs on ESXi, without issue. Technically, if your OEM software was tied to hardware that is no longer functional, I believe the EULA states that the OEM copy is to be destroyed, as it's legally tied to the hardware that it came with.
The reason I ask is the XP OEM is to be tied to hardware... with ESXi its not really tied to hardware at all and can be moved around differnt system etc.
Your most likely correct on the oem. Thats why they have excpetions in there DataCenter and Enterprise licensing for servers. I can contact my MS rep if you really want a real answer.