This is the product key linked to Windows 7 ultimate version. It is provided with every licensed and legitimate purchase of a Windows 7 ultimate PC or laptop. The product key is mentioned in the certificate of authenticity that is supplied with the laptop. The sticker contains the number that needs to be reloaded every time your laptop needs the operating system to be reinstalled or reloaded. However, you need to be a registered and legitimate user of the product key as every product key is linked with an authorized purchase. Hence, if you are trying to download the product key for free without having purchased a similar laptop or computer with the operating system, chances are that you can only use the trial version for a limited time period. If you face any problem reloading the product key there are instructions that are provided on the official Windows site.
The ultimate product key can be found on the Windows official site and it is available for download for registered users. In case you face problems with the number having been misplaced, you can download it again from the legit sources offered by Microsoft.
Free download of the product key comes only in the trial version.