You can find  your Windows 7 product key on the bottom of your computer (if it was bundled with Windows 7), inside the original Windows 7 package (if you purchased retail media), or in a confirmation e-mail (if you purchased and downloaded Windows 7 online.)

You can go to the Microsoft website to see an example of a product key (certificate of authenticity or COA) stickers.

If you can't find your product key, you might need to buy a new one. To learn how, see Get a new Windows 7 product key.

If you receive an error indicating that your product key is not valid when installing Windows 7, see Windows 7 activation error: invalid product key.