citando link :
In short; It will work, but is not allowed:
As stated on Microsoft.com:
You are required to support the license on that original PC, but you cannot support a license that has been moved from a PC that you manufactured to one that you did not. This is one of the key reasons why an OEM System Builder License can’t be transferred.
Se você tivesse uma licença não OEM, teria sido correto virtualizar sua Windows, desde que você desative o antigo.
fonte: link
Além disso, talvez você não consiga obter a chave de licença do Windows 10, pois as chaves OEM são na maioria das vezes gravadas no BIOS / UEFI.
A execução de um backup / imagem da instalação original em uma VM acionará a reativação do Windows, que falhará, já que as licenças OEM estão, em geral, vinculadas à placa-mãe. A partir da FAQ oficial da Microsoft:
What happens if I change my motherboard?
As it pertains to the OEM license this will invalidate the Windows 10 upgrade license because it will no longer have a previous base qualifying license which is required for the free upgrade. You will then have to purchase a full retail Windows 10 license. If the base qualifying license (Windows 7 or Windows 8.1) was a full retail version, then yes, you can transfer it.