If your copy of Windows did not pass the validation check and you believe that you have purchased a genuine copy of Windows, we have resources to help you. When the validation check fails, you receive a message that explains why Windows did not pass the check. You are directed to a customized Web page that has details about what caused the failure and recommendations for how to resolve the problem. This page contains a section with troubleshooting steps. One of these steps will let you check whether you can use the online Product Key Update Tool.
If a genuine product key was included with your computer, but Windows was incorrectly installed with an invalid product key, the Product Key Update Tool helps convert your computer to a genuine status without having to purchase a new copy of Windows. If you are using the Windows Update Web site, you are returned to that Web site, where you can obtain downloads that do not require validation.