When I install Windows 10 and I changed the settings .......

Hi,

When I install Windows 10 and I changed the settings .. For example, I add a language and modify the screen resolution of the Retina display to others .. and I deleted Windows 10 and install Windows again .. I found that the previous amendments remained to the new version .. even after formatted the Mac and terracing the parallels one more time .. my question: where are the saved in system and how can I delete it? Can you explain to me, step by step how to delete it?

Regards