You can find out the serial number in Windows 7 by using a third-party program or locating the serial number on the CD package or the computer. Microsoft encrypts the serial number in Windows 7, making it difficult to access the serial number through conventional means, such as searching for the number in the registry.
- Check the packaging
Look inside or on the back of the packaging that came with the CD. Check for a strip of tape that lists the serial number across the CD sleeve or on a box within the product package.
- Search the computer
Some newer model laptops and desktops have the Windows 7 serial number printed on the computer casing. Turn the laptop over, and check for a serial number on the bottom corner. If you have a desktop, look on the back of the computer tower for stickers that may contain the serial number.
- Use a third-party program
Download a product key finder from an online resource, and install it on your system. Follow the instructions for installation, and run the program. The program searches the computer for the serial number and displays it in a series of numbers and letters separated by hyphens.