Windows Anytime Upgrade is an online process for upgrading from one version of Windows to another (for example, from Home Premium to Ultimate). If you upgrade Windows using Windows Anytime Upgrade, your proof of license is identified by:

• The genuine Microsoft proof of license label from your original software purchase,
• A digital license stored in the digital locker at Windows Marketplace,
• Proof of purchase from a Windows Anytime Upgrade merchant that identifies the software.

You must have all three of these components to have a valid proof of license for your upgrade.

If both of the following are true, it is a strong indication that your upgrade purchase was genuine:

• You purchased the upgrade from a Microsoft Merchant of Record (MOR).
• When accessing your digital locker, the security certificate is issued to digitallocker.windowsmarketplace.com and was issued by Microsoft Secure Server Authority. To view the certificate, while accessing your digital locker, right-click the page and select Properties. In the Properties dialogue box, click the Certificates button. Or, if using Microsoft Internet Explorer 7, click the Security Report button to the right of the browser address field, and then click View Certificates.

For more information, visit the Windows Anytime Upgrade site.