what is the product key of my windows
Product key. Product key on a Proof of License Certificate of Authenticity for Windows Vista Home Premium. A product key, also known as a software key, is a specific software-based key for a computer program. It certifies that the copy of the program is original. Activation is sometimes done offline by entering the key, or with software like Windows 8.1, online activation is required to prevent multiple people using the same key.