Hardware Identification (HWID)
Definition - What does Hardware Identification (HWID) mean?
Hardware identification (HWID) is a method used by the Windows operating system (OS) to identify the hardware platform on which it is installed.
Techopedia explains Hardware Identification (HWID)
Hardware identification is a security measure used by the Windows operating system on activation. A string called a Hardware Identifier (HWID) is generated by the operating system when it is installed for the first time. This identifier represents all the hardware devices attached to the host computer and is transferred to Microsoft. Every 10 days and after every reboot, a new HWID is generated which is compared with the one generated at the time of installation. If both the IDs are close to each other, then the operating system assumes that it is running on the same device. Otherwise, the operating system needs to be activated by Microsoft.
The disadvantage of this approach is when a user changes components like RAM, graphics cards and sound cards, thus generating a considerably different HWID on the subsequent reboot. This can cause the operating system to be blocked, and the user must then contact Microsoft customer support to report their changes.