Windows product key can typically be found on the original Windows CD/DVD box or somewhere on the PC’s case. If you have somehow lost the product key, you can easily find it with free tools. As you may know, Windows saves the product key in the registry and the key can recovered with the help of third-party tools.
Windows 8 Product Key Viewer is a portable utility to recover Windows XP, Vista, Windows 7 and Windows 8 product key in a jiffy. The tool lets you save the retrieved key in a text file as well. Download and run the utility to view the Windows product key.
This is a free software and doesn’t require an installation. Supports both x86 and x64 versions of Windows XP, Vista, Windows 7 and Windows 8 operating systems. You can download Windows 8.1 Product Key Viewer from the developer’s page. We tested it on x64 versions of Windows 8/8.1 and can confirm that it works as claimed.