The Windows XP Professional CD Key follows this format: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX

It consists of five groups of five alphanumeric characters. The key is typically found on a Certificate of Authenticity (COA) sticker affixed to the computer case or on the CD sleeve for retail versions.

Introduction Windows XP Professional, released by Microsoft in 2001 and supported until 2014, was one of the most iconic operating systems in PC history. A core component of its installation and activation process was the Product Key (often called a CD Key) – a 25-character alphanumeric code required to install and activate the software.