HI Kris,
Since you already upgraded from Windows 7 to Windows 10 last year, you will no longer need a product key for activation should you decide to perform a complete wipe and clean install. For more information about digital entitlement and how activation works in Windows 10, you may refer to this support article.
If you're trying to create a complete backup of the latest Windows 10 operating system, you'll need to create an installation media using the Media Creation tool. You may check this link for a thorough explanation of how it works.
On the flip side, you can also create either a recovery drive or a system repair to back up system files. To create a system repair disc for CD/DVD, type recdisc in Cortana/search bar and click the first result:
Make sure to insert the CD/DVD in your computer's CD reader (or a portable CD reader if it's not available) and select the correct drive. Since this will back up a lot of files, it will take some time to finish:
If you prefer using a USB or thumb drive, you may refer to this support article for the steps in creating a recovery drive.
Feel free to post back if you have any other questions or concerns. We'll be here to assist if ever you need us.
