En ezt talaltam: http://www.microsoft.com/oem/en/licensing/sblicensing/pages/licensing_f…
"After an OEM software license has been installed on a PC, the license may not be installed on or transferred to another PC."
Es itt a PC az a virtualis gepet is jelenti. Vagyis normal Windows eseten lehetne varialni, hova installalsz, OEM-re ez nem igaz. Vegulis ez a fo kulonbseg az OEM es a retail kozott, nem a doboz - es ezert is kerul a retail tobbe.