Removing and Reusing Windows 7 Product Key?

Hello,

A few months ago I installed windows 7 via parallels on my macbook. However, since I will be getting a new PC with windows 8 pretty soon, I no longer feel the need to have windows 7 on my mac. I purchased the full retail version of windows 7 and I am thinking of selling it now. The problem is that I don't know if I have to deactivate or unregister the product key. However, what I did is remove windows 7 by deleting the virtual machine and all files. Would anyone know if removing the virtual machine would be enough for someone else to be able to reuse my product key. And is there a way of knowing if my product key is registered?

Thanks

My experience on this concurs with what Noel wrote. I believe the hardware ID associated (at activation) with that key remains until it is overwritten.

This seems to be covered by a question that may be posed during online or phone activation when it asks "How many PC's is this copy of Windows installed upon?" which I've only been asked if the key is already activated elsewhere, and whether its partition is deleted already or not. The only answer one can give to this question is "One" to proceed with activation. This appears to be giving consent to have the key deactivated on any previous installs.

However if you feel better deactivating the key itself then that is covered by Product Key Number - Uninstall and Deactivate in Windows - Windows 7 Help Forums. All I have ever done to achieve this is delete the OS partition which is the correct way to uninstall Windows itself.

NoelDP said:

There is (contrary to myth) NO way to 'unactivate' Windows.

MS's Activation servers record every activation attempt for every Key - and there is no way to inform them of having uninstalled a license (it'd be a pointless exercise, really, since there are too many ways to do that in ways which would be impossible to record that would make a mockery of any attempt to record it).
Simply uninstalling is sufficient to allow the new owner to install and activate.

When you sell it, you must include all relevant paperwork (preferably including the original receipt for the purchase), and the original disks. You should advise the purchaser that telephone activation will almost certainly be required, but that it should be OK.

Make sure that you delete all VMs/partitions with your installs on.

There is an option on parallels to remove the virtual machine by clicking File > Remove. Then it is moved to the trash. Would that be considered a legit way of deleting it?

Thank you guys very much!