I have a Dell Inspiron 3650 desktop that came with Windows 7 installed, but the recovery disc it came with contains Windows 10. I was under the impression that I could use that disc to upgrade to Windows 10 at any time. I'm ready to do the upgrade but I have no idea how to do it, and there does not seem to be any instructions online. I do not want to do a fresh install and lose everything I have on the computer.
Discard the disc it will be an old build of Windows 10...
Use the Windows 10 Media Creation Tool to perform an in place upgrade to Windows 10 Version 1709:
Note if you are installing in English, the Media Creation Tool will assume all Windows 7 English Installs are English US and not English UK. To Upgrade to Windows 10 Version 1709 English UK create a Bootable USB and then launch the setup from it to begin the in place upgrade.
More details about the in place upgrade are available here: