The Fresh Start feature in Windows 10 basically installs the new copy of Windows 10 in your computer. This installation is completely different from the other installation of Windows.
To perform the Fresh Start in Windows 10, it is must that the Windows Defender should be activated. If you have any other antivirus on the computer, remove/disable the same and have the Windows Defender activated first.
Here are the steps to be followed to perform the Fresh Start.
1. Open Windows Defender through the setting App or anyway you find it easier.
2. From the top left corner Open the Menu.