Product Key

Definition: The product key, often called a CD key, is a usually unique, alphanumeric code of any length required by many software programs during installation. Unique product keys help software manufacturers ensure that each copy of their software was legally purchased.

All Microsoft Windows operating system versions require the entry of unique product keys during the installation process. Below are examples of what these product keys look like:

Windows 7: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows Server 2008: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows Vista: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows Server 2003: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows XP: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows 2000: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows ME: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows 98: xxxxx-xxxxx-xxxxx-xxxxx-xxxxxWindows NT: xxxxx-xxx-xxxxxxx-xxxxxWindows 95: xxxxx-xxx-xxxxxxx-xxxxx

Important: See my Windows Product Key FAQ for more information about Windows keys.

Many other operating systems and most other programs from nearly every software maker require product keys. Some, including Microsoft, often require product activation in addition to product keys to help further ensure that software is obtained legally.

Since product keys are required during installation, finding that you've lost a product key could be a serious problem if you need to reinstall a program. Luckily, there are a number of ways to retrieve lost product keys:

Find Microsoft Windows Product Keys

Find Microsoft Office Product Keys

Find CD Keys Using a Free Key Finder Program

Find CD Keys Using a Premium Key Finder Program

Important Note: The unique product key entered for an operating system or a software program is typically stored in an encrypted format in the Windows Registry, making finding one very difficult without some help. The above linked guides should help find just about any CD key you may be looking for.