+ 0 Votes Reponse To Answer databaseben 2 years ago ultim.. - i'm not here to justify the incorporation of the product key / licensing systems. i'm just explaining that product keys are a method used to prevent piracy. product keys are registered by the manufacturer after the product is setup on a system. and the manufacturer will only allow a product key to be activated in accordance to the licensing agreement. so while some product keys can only be activated a single time, there are cases where a product key can be activated on several more computers, as allowed by the manufacturer.also, there is a mention that hdd can be cloned and used on other systems. but this is no longer true. when windows is setup on a system, it takes an inventory of all the components of that system. if i recall, it inventories 10 components and acquires their internal serial codes of each component and builds a "hardware hash". and the hardware hash is analyzed "every time" windows is booted up.in doing so, if that hardware hash is transferred to another computer which appears to be identical, the internal serial codes won't match the hardware hash and windows won't boot. again, this is another anti piracy feature.