How to Find My Microsoft License Number for My Operating System

By Adrian Grahams

Check the retail CD/DVD case for your Windows product key sticker.
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The license number for computers running Microsoft Windows is known as the product key, which consists of 25 alphanumeric characters divided into five groups of five characters. You should find the key on a sticker attached to the retail product CD/DVD case or on a label affixed to your computer if it shipped with Windows installed. If you can't find the product key sticker, use free third-party software to retrieve the product key from the operating system itself.

Check the front and back of the Windows retail product jewel case for a multi-colored, yellow or orange sticker. If you can't see the sticker on the case, open it and check the installation disc holder inside. If your computer shipped with Windows installed, check the side and rear of a desktop PC or the underside of a laptop computer for the sticker. Follow the next steps if you can't find the sticker or it's worn away and you can't read the key.

Download and install a free Windows product key finder tool, such as Magical Jelly Bean Key Finder, Product Key Finder or Belarc Advisor.

Launch the product key finder program and scan your system. Magical Jelly Bean Key Finder and Belarc Advisor will return results for all supported programs, including the Windows operating system and Microsoft Office products. The smaller Product Key Finder tool will return only Windows operating system information.

Select the entry for your Windows version to display the product key and other installation information. The program will list the product key as either the "CD Key" or "Product Key" in the program window.

Write down the product key carefully so that you can reference it easily if you need to activate Windows on your computer or upgrade to a newer version of Windows.


Many free utilities prompt you to download additional software or upgrade to premium versions. Ensure you select only the product key finder component during the installation process.

Contact Microsoft Support if you need to buy a new product key for Windows.