You can still use the built-in recovery tools to revert your Dell laptop to factory settings in case it fails to boot to Windows. On booting the laptop, press F12 consecutively, the Dell logo shows, and F12 speeds up into the One-Time Boot Menu. On that, pick SupportAssist OS Recovery when possible, and then pick Reset to Factory State and proceed with what the screen displays. This will drop into a standalone recovery interface, which will not need to start Windows. The process will delete all personal files, settings, and apps, and therefore, it is advisable to copy anything important before handing it over. This way you can restore a Dell laptop to factory settings.