Look for the Microsoft Vista product key on the product manual or on a sticker attached to the computer. Alternatively, use key finder programs to recover the product key from within the system registry. The product key has an easily identifiable format: 25 alphanumeric characters divided into five groups.
Unlike Windows 95 and 98, Windows Vista hides the product key using encryption, which means a manual search in the registry doesn't work. A more appropriate method for product key retrieval is using a key finder program, some examples of which include Belarc Advisor, LicenseCrawler, Magical Jelly Bean Keyfinder and Winkeyfinder. Many key finder programs are effective and available for free, but their commercial counterparts may offer better features such as finding product keys for other programs and faster scan times.
Other possible locations of the product key are the original install disc and, for digital purchases, the invoice or confirmation email. Finding the product key is important when installing, reinstalling or activating Windows Vista. If the original product key is truly lost, buying a new copy of Windows Vista may be necessary. A cheaper alternative is to request a replacement product key from Microsoft. Original computer manufacturers may also offer new product keys for their computers that came with pre-installed Windows.