How does Microsoft identify the computer's hardware?
Microsoft Product Activation detects the hardware configuration on which the product is being installed and creates hash values for that configuration. A hash is a value mathematically derived from another value - in this case hardware configuration values. Product Activation does not scan the customer's hard drive, detect any personal information, or determine the make, model or manufacturer of the PC or its components. Microsoft uses hash values out of respect for users' privacy. A hash value cannot be backwards calculated to determine the original value. In addition, Microsoft only uses a portion of the original hash values. Together, these hash values become the complete hardware hash that is included in the installation ID.
Can hardware components be changed and upgraded?
Product Activation is able to tolerate a certain degree of change in a hardware configuration by allowing a current hash value to have a degree of difference from the hash value that was originally activated. As a result, users can change their hardware without the product believing it is on a different PC than the one it was activated on. If the user completely overhauls the hardware making substantial hardware changes (even over long periods of time), reactivation may be required. In that case, users may need to contact to contact a Microsoft customer service representative by telephone to reactivate.
How does product activation determine tolerance? In other words, how many components of the PC must change before I am required to reactivate?
Common changes to hardware such as upgrading a video card, adding a second hard disk drive, adding RAM or upgrading a CD-ROM device will not require the system to be reactivated.
Specifically, product activation determines tolerance through a voting mechanism. There are 10 hardware characteristics used in creating the hardware hash. Each characteristic is worth one vote, except the network card which is worth three votes. When thinking of tolerance, it's easiest to think about what has not changed instead of what has changed. When the current hardware hash is compared to the original hardware hash, there must be 7 or more matching points for the two hardware hashes to be considered in tolerance. If the network card is the same, then only 4 additional characteristics must match (because the network card is worth 3, for a total of 7). If the network card is not the same, then a total of 7 characteristics other than the network card must be the same. If the device is a laptop (specifically a dockable device), additional tolerance is allotted and there need be only 4 or more matching points. Therefore, if the device is dockable and the network card is the same, only one other characteristic must be the same for a total vote of 4. If the device is dockable and the network card is not the same, then a total of 4 characteristics other than the network card must be the same.
Are the changes cumulative? In other words, if I change one component today and one tomorrow, is that two component changes?
The changes are cumulative; however, if a user is asked to reactivate, the hardware profile is reset to that new configuration.
What are the 10 hardware characteristics used to determine the hardware hash?
The 10 hardware characteristics used to determine the hardware hash are: Display Adapter, SCSI Adapter, IDE Adapter, Network Adapter MAC Address, RAM Amount Range (i.e. 0-64mb, 64-128mb, etc), Processor Type, Processor Serial Number, Hard Drive Device, Hard Drive Volume Serial Number, CD-ROM/CD-RW/DVD-ROM.
Does product activation deter hard disk cloning by comparing these hard disk hashes?
One of the forms of piracy that Product Activation guards against is hard disk cloning. Not all forms of hard disk cloning are illegal. However, by comparing the hardware hash originally activated to the current hardware hash, hard disk cloning can be deterred by requiring re-activation if the hardware hashes are substantially different.
If I reformat my hard disk, is reactivation required?
If the hard disk is reformatted and the software is reinstalled, reactivation will be required. The same grace periods for activation apply in this situation. Reactivation on the same PC can be completed as many times as required. The activation can be completed via telephone or Internet.