

The theory behind HWID is to ensure that the operating system is not being used on any device other than the one for which it was purchased and registered. If the two HWID numbers differ too much then the operating system will shut down until Microsoft reactivates the product.

Every 10 days and at every reboot the operating system will generate another HWID number and compare it to the original to make sure that the operating system is still running on the same device. The HWID identifies the hardware components that the system is utilizing, and this number is communicated to Microsoft. As part of the Product Activation system, a unique HWID number is generated when the operating system is first installed. Short for Hardware Identification, a security measure used by Microsoft upon the activation of the Windows operating system.
