[Data]

I wanted to get to the bottom of this re activating windows and changing hardware thing.

What does trigger Windows to reactive?

I found this, Bill wont mind us passing the information on.


 How does MPA identify the computer's hardware?

MPA detects the hardware configuration for the computer where the product is being installed, and then MPA creates a hardware hash value for that configuration. A hash is a value that is mathematically derived from another value. In this case, the hash is derived from the hardware configuration values. MPA does not scan the customer's hard disk, detect any personal information, or determine the make, model, or manufacturer of the computer or of its components. MPA uses hash values because of respect for users' privacy. A hash value cannot be backward-calculated to determine the original value. Additionally, Microsoft only uses a part of the original hash values. These hash values are combined to form the hardware hash.

Can I change or upgrade my hardware components?

MPA can tolerate some change in hardware components by allowing a degree of difference between the current hash value and the hash value that was originally activated. Users can change hardware components without having to reactivate the product. If users make substantial changes to their hardware components, even over long periods of time, they may have to reactivate the product. In that case, users may have to contact a Microsoft customer service representative by telephone to reactivate.

How does MPA determine tolerance? How many components of the computer can I change before I have to reactivate?

Common changes to hardware, such as upgrading a video card, adding a second hard disk, adding RAM, or upgrading a CD-ROM or DVD-ROM drive, do not require reactivation.

Specifically, MPA determines tolerance by using a point system. Ten hardware characteristics are used to create the hardware hash. Each characteristic is equal to one point, except the network card, which is equal to three points. Tolerance is determined by what has not changed, instead of what has changed. If the current hardware hash is compared to the original hardware hash, there have to be seven or more matching points for the two hardware hashes to be considered in tolerance. For example, if the network card, which is equal to three points, remains the same, only four additional points have to match. If the network card has been changed, a total of seven points have to match. If the device is a portable computer (specifically a dockable device), additional tolerance is allotted and only four matching points are required. Therefore, if the device is dockable and the network card has not changed, only one additional point has to be the same, for a total of four points. If the device is dockable and the network card has changed, a total of four points have to match.

Are the changes cumulative? If I change one component today, and then change one component tomorrow, is that considered two component changes?

The changes are cumulative; however, if a user is asked to reactivate, the hardware profile is reset to the new configuration.

What are the 10 hardware characteristics that are used to determine the hardware hash?

The following 10 hardware characteristics are used to determine the hardware hash:
Display adapter
SCSI adapter
IDE adapter
Network adapter media access control address
RAM amount range (for example, 0-64MB or 64-128MB)
Processor type
Processor serial number
Hard disk device
Hard disk volume serial number
CD-ROM/CD-RW/DVD-ROM drive


Now we know, kind of

Things to note:

The motherboard can have a number of these hardware components on these days, normally the network card and IDE adapter at least and I noticed, from the article, that the network card scores the highest. So a motherbraod change is the last thing you want to do.

One of the things it looks at is the Processor serial number, on some motherboards you have the option to turn off the unique serial number, I don’t know if it would definitely stop windows from getting the serial number but I have mine turned off just in case  

[photostill]

That's a nice list of changes that it watches. Funny thing is I've never had one ask for reactivation. About the only thing I've not changed on a computer is the CPU. I'm one of those that believe usually when you lose the CPU under an aging computer, you ditch the components as most of it's useful life is gone.

I tend to use cases again but not power supplies. Again by the time you usually need to replace a power supply, the hardware requirements have all went up for newer stuff, making it not suited to the application when everything thing else is updated.

Other than the CPU, the list reads like a change out list to me, having done most of the other items listed if not all.