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Windows XP


Microsoft Windows XP Product Activation

By: Arie Slob

Windows XP OK, there's a lot of confusion about the Windows Product Activation (WPA) Microsoft uses in Windows XP. I will try to explain some of the techniques involved, as well as Microsoft's motivation behind it.

To start with the easy part: Microsoft's motivation. Microsoft wants to end casual piracy. Casual piracy is when (for example) you buy one copy, and install it on all your family members PC's.

No matter how we think about it, the (current) EULA (End User License Agreement) clearly states that you can only install the OS on one machine. Microsoft hasn't released licensing details yet for Windows XP, and has been urged by several sources to consider adding a "home" license, allowing the installation of Windows XP on more then one PC.

OK, I agree, there's a lot more to it. It's another inconvenience, especially to us "advanced" users who tinker a lot with their PCs, always adding/upgrading stuff. But anyway, let's take a look at the technical side of WPA.


Keep in mind that WPA and Product Registration are two different things. Product registration has always been voluntary and will continue to be so.

WPA is mandatory. If you don't activate Windows XP within 30 days, you will have to activate it on the next startup. Activation can be done over the Internet (preferable) or via telephone.

WPA works by validating that the software's product key has not been used on more PC's than is allowed by the software's license. Product key information, in the form of the product ID, is sent along with a "hardware hash" to Microsoft's activation system during activation. Activations on the same PC using the same product key are unlimited.

Now there are several questions surrounding the "hardware hash" that is generated. Microsoft is quite tight-lipped about this one. The "hardware hash" is a "fingerprint" of your PC's hardware, but it is not exactly clear which hardware is used to generate the hash. What seems clear is that more than one piece of hardware is used.

It is also not clear what hardware changes would trigger a reactivation, with Microsoft representatives only suggest that it would need to be "a substantial change". They do admit, however, that if you make "many" changes, a reactivation will eventually being triggered (i.e. changes are cumulative). So, for example, 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. If you need to reactivate you'll need to call Microsoft, and they will issue another confirmation ID.

According to Microsoft they will err on the side of the user, so that you are not denied your right to use the product. Microsoft says it will reactivate with no questions asked, realizing that customers will need to use phone reactivation for various reasons and won't make it difficult.

The only information needed for a product activation is the installation ID, which is a combination of the product key and hardware hash. No personal information is needed. Activation over the Internet only takes a few seconds, activation by telephone takes a few minutes.

If you choose to activate using the telephone, you will need to read the 44-digit installation ID to the support representative in the activation center. You will then be given a 42-digit activation ID, which you have to enter. The support rep will wait till you finish, to make sure that the activation was successful. Microsoft did usability testing of both numeric and alphanumeric installation and confirmation IDs. Though the IDs could have been made shorter using alphabet characters, Microsoft learned through usability testing that users' interactions with the customer service representatives were substantially more error-free when the ID's were all numeric. There were fewer misunderstandings with numerals than with alphabet characters. Because the conversations were more error-free, the calls were shorter and customer satisfaction with the telephone activation process was improved. This are the main reasons that Microsoft chose to use only numerals.

According to Microsoft, Product Activation does not scan your hard drive, detect any personal information, or determine the make, model or manufacturer of the PC or its components.

If you need to reinstall Windows XP on the same machine, you won't need a new license. If you do not (re)format the hard disk prior to reinstalling, Windows XP will remain activated (the activation data is stored on the hard disk). Reactivation on the same PC can be completed as many times as required.

Another thing to remember is that customers acquiring their licenses through one of Microsoft's volume license programs (e.g., Select, Open, Enterprise, etc.) will not have to activate those licenses. Microsoft's volume licensing agreements are not limited to the Select License program. Microsoft also offers smaller companies the ability to acquire volume licenses at a discount under the Microsoft Open License program. Customers can qualify for Open License by purchasing as few as five product licenses. Almost all but the smallest businesses should be able to qualify for Microsoft Open License.