A product key refers to a 25-character code that is taken in use to activate Windows and assist in the verification of that Windows hasn't been used on more PCs than the Microsoft Software License Terms allow. What exactly is Microsoft Visio product key? If your computer came preloaded with Microsoft Windows, the software product key is generally a multicolored, Microsoft-branded sticker present on your PC case. For Microsoft Office, you can discover the sticker on the installation disc that escorted the computer. With Visio on your PC or mobile device, you will be able to organize complicated ideas visually. You can begin with hundreds of templates, including flowcharts, timelines, floor plans, and more. You will be able to, and connect shapes, text, and pictures to portray relationships in your data.