How does Microsoft identify the computer's hardware? Can hardware components be changed?

Microsoft Product Activation detects the hardware configuration on which the product is installed and creates a hash value for that configuration. Product Activation does not scan the hard drive, detect any personal information, or determine the make, model, or manufacturer of the computer or its components. Hardware components can be changed; however, if you completely overhaul the hardware, reactivation may be required. In that case, you'll need to contact a Microsoft customer service representative by telephone to reactivate.  more

Microsoft Product Activation detects the hardware configuration on which the product is being installed and creates a hash value for that configuration. Product Activation does not scan the hard drive, detect any personal information, or determine the make, model, or manufacturer of the computer or its components. Hardware components can be changed; however, if you completely overhaul the hardware, reactivation may be required. In that case, you'll need to contact a Microsoft customer service representative by telephone to reactivate.  more