Será mesmo assim? Não o poderei instalar noutra máquina? (negrito meu)
Reading Vista’s EULA sometimes helps make a decision:
13. UPGRADES. To use upgrade software, you must first be licensed for the software that is eligible for the upgrade. Upon upgrade, this agreement takes the place of the agreement for the software you upgraded from. After you upgrade, you may no longer use the software you upgraded from.
This means that upgrading to Vista from XP voids the XP key.
