How to Validate a Windows XP Product Key
If you have purchased a used computer with Windows XP pre-installed or are about to purchase a used copy of the operating system itself, you want to be sure that you are getting the real thing. Microsoft has several anti-piracy measures in place for Windows XP. You can use these features to validate the product key of an existing Windows XP installation, or confirm that a product you are about to purchase is genuine.
Validating a Windows XP Product Key
Open Internet Explorer and browse to the Genuine Microsoft Software validation page. Click the blue "Start Windows Validation" button in the upper-left corner of the page. Click the "Run" button in the dialog box that appears, and then skip to Step 4. If you do not see a "Run" button, continue to the next step.
Click the yellow bar across the top of the Internet Explorer window if you receive a message saying "This site might require software from Microsoft Corporation." Click "Install This Add-on."
Click "Install" if an "Internet Explorer Security Warning" window appears asking if you want to install software. You may receive this message more than once. The website installs the Windows Genuine Advantage add-on for Internet Explorer, and the page reloads. Click the "Start Windows Validation" button again.
Examine the results displayed after the validation process is complete. If you are using a valid Windows XP serial number, the screen displays the message "Thank you for completing the validation process and for using genuine Microsoft software."
Validating a Windows XP Package
Examine the Windows XP packaging for a printed certificate of authenticity. The certificate of authenticity is generally blue and green, and should have a holographic metal strip running through it. The printed certificate of authenticity is included with retail packages of Windows XP. If your computer is manufactured by a large company such as Dell, HP or Gateway, the certificate of authenticity may come in the form of a small label stuck to the computer permanently.
Examine the Windows XP packaging for a yellow and white label with a 25-character product key. The label contains a vertical security strip, much like many bank notes. If you have a computer with a certificate of authenticity affixed, you may not have a yellow and white product key label.
Examine the Windows XP disc. The disc has a holographic design that changes color when you shine a light against it. Additionally, the design has a scalloped pattern around the edge of the CD.