If you encounter an anti-counterfeiting message in Windows XP, it is possible that your copy of Windows XP was illegally produced, but there are other reasons for this message as well. While it is illegal to install and use the Windows operating system without paying for it, sometimes people encounter this message without knowing why it is being displayed. If this has happened to you, there are a few things you can try to see if you can make the message go away.
Enter the registration key into your operating system. If the computer is displaying a message asking you to activate the operating system, you may have neglected to provide a registration key when you installed the software. In newer versions of the Windows operating system, such as Windows Vista and Windows 7, you can run the operating system for around 30 days before you have to enter a registration key, so it's easy to forget to perform this simple task. To fix this type of message, enter your authentic registration key in the prompt and allow the computer to activate itself.
Reinstall your operating system. If you are confident that your copy of Windows was legitimately purchased but you are still receiving counterfeit notifications, the operating system may have a corrupted file that is preventing the Windows Genuine Advantage program from operating correctly. Use your Windows installation CD to perform a complete operating system reinstallation. Once this is complete, activate your operating system to confirm that you are not receiving any more counterfeiting messages.
Purchase a legitimate version of your operating system. If you are receiving a message that your operating system may not be legitimate and you are unable to activate it, you may have purchased an illegally made copy of Windows. In the counterfeit notification window, choose the "Get Genuine" option to be taken to the Microsoft website to purchase a legitimate version of the operating system. Using legitimately purchased operating systems will help protect your computer since you will be able to download security updates for your machine to protect against hackers and other online threats.