Installation ID/ Activation

[Bad boy Warrior]

Im trying to understand Activation and installation ID. When you activate windows vista (possibly xp too) it asks you to send an installation id consisting of 50 numbers i think. You also have to have a valid PID before installing.

My question is anyone can have one product key but a different installation ID therefore windows can be activated on 2 pcs even if you have one license or PID - is this the case or how does the installation ID know what the product key is to activate? or if im completely wrong please explain.

Thanks

[cluberti]

I can't speak to specifics, but what happens in general terms is that when you install Windows, a hardware hash and an installation ID is generated. When you enter your PID and activate, the Vista machine and the activation servers store the hash based on an already stored hardware hash, the PID and the installation ID, as well as mark that PID "activated".

- If there is an attempt to reactivate an already activated PID before a specified time has passed since the PID was first activated, and the machine associated with that PID has not checked in for a specific number of re-validations (I believe it's 3 or 4 missed re-checks, or 2 years approximately), activation will fail.

- If there is an attempt to move an activated copy onto another box (imaging, changing out too many parts, etc), the system hash will not match the hash previously stored and activated, and if the hash differs greatly the box will need to be reactivated.

You can reactivate an already-activated Vista PID on a second machine if you call the clearinghouse 800# and go through the phone activation, and theoretically you could have 2 (or more) machines activated concurrently on the same PID. The fun begins when those machines all check in to reactivate (I think the timeframe is every 180 days) - if the servers work as I understand them to be designed, all but 1 of those machines will fail reactivation thus limiting this practice's effectiveness. Re-checking was not done on XP or 2003, so if you managed to activate multiple machines against one PID, they would work indefinitely.