When you turn on your computer for the first time, Windows might display a very insistent request to activate the operating system. This is an anti-piracy tool that is designed to discourage people from buying a single copy of Windows and installing it on more than one computer.
You won't see Windows Product Activation if your computer came from a major manufacturer with an OEM version of Windows, or if your company has a volume licensing agreement with Microsoft. But if you bought your copy of Windows XP at retail, or as an upgrade from an earlier version, you must run the activation routine within 30 days after installation. You might also see a request for authentication if you replace several major components (such as the motherboard and CPU) at the same time. If you don't activate your copy of Windows, it stops working after a month.
Product activation might appear to be a serious intrusion on your privacy, but it really isn't that bad. Microsoft may conduct some aggressive and even offensive business practices, but product activation is not usually one of them. They have a legitimate right to enforce the product license that limits each copy of Windows to a single computer. If you run Windows on two or more computers, you must buy a license for each one.
Microsoft does offer a small discount on licenses that allow you to install your copy of Windows on additional computers. Each license includes a new Product Key and the right to use Windows on a separate system. For information about additional licenses, go to http://www.Microsoft.com/windowsxp/pro/howtobuy/addlic.asp. The discount is based on the full retail price, so you might find an even lower price from a computer superstore or office supply retailer, especially when they're running a special sale or promotion.
Many people suspect that product activation is a thinly disguised attempt by Microsoft to collect personal information about you and your computer. However, nobody has found any evidence that they're doing anything but trying to thwart software pirates. Their official line is "At no time is personally identifiable information secretly gathered or submitted to Microsoft as part of activation. Product Activation is completely anonymous."
If your copy of Windows requires product activation, Windows uses the unique Product Key code supplied with the software CD to create an activation ID code and a hardware hash code during installation that contains information about these components:
The type of CPU
The CPU's serial number
The amount of RAM
The type of graphics adapter
The IDE controller
The SCSI adapter (if any)
The MAC address of the network adapter
The make and model of hard drive
The hard drive's volume serial number
The type of CD or DVD drive
Whether the computer includes a docking station or a PC Card socket
During Setup, Windows offers to run the activation process, but unless you have already configured your Internet connection or your modem, you probably can't make the connection yet. You have 30 days to complete the activation, so it's okay to skip it until you have finished the setup process; Windows will keep reminding you to activate.
You can activate your copy of Windows through the Internet, or by making a voice telephone call to Microsoft. If you have an Internet connection, choose the online method; it's much easier than reading a 50-digit code to a service representative and typing a 42-digit installation ID code into the computer by hand.
If Product Activation sends Microsoft an ID code that has already been used, it compares that ID code with the hardware hash of the earlier activation. If everything matches, there's no problem, and they accept the new activation. If four or more components have changed, or if it has been less than three months since the last time you made major changes, Microsoft rejects your request for activation.
When the online activation rejects your request, it displays a telephone number and asks you to call with an explanation. If you have a reasonable story, the customer service agent who takes your call may believe you and tell you how to activate. But if you try to use the same Product Key to activate two or more completely different systems within a week or two, or if you use the same code on a dozen different machines, they will probably refuse to help.
It's important to understand that product activation is not the same as registration. You must activate your copy of Windows, but registration is purely optional. If you don't want to tell Microsoft who you are and how you use Windows, you don't have to register.