Microsoft provides official instructions for finding product key codes and methods for verifying the authenticity of packaged software on the "How to Tell" section of the official Microsoft.com website. Microsoft key codes are alphanumeric and 25 characters long, with each set of five characters separated by a dash symbol.
The precise location of Microsoft product key labels varies from product to product. Newer products have a Certificate of Authority label that is attached to the outside of the product packaging. These include the product name and key code. Microsoft products also include a product key label, which is a white or orange label that comes with the installation media.