When your computer is unable to boot to the operating system even after repeated attempts, it automatically starts Dell SupportAssist OS Recovery.
Dell SupportAssist OS Recovery is a standalone tool that is preinstalled in all Dell computers installed with Windows 10 operating system. It consists of tools to diagnose and troubleshoot issues that may occur before your computer boots to the operating system. It enables you to diagnose hardware issues, repair your computer, back up your files, or restore your computer to its factory state.
You can also download it from the Dell Support site to troubleshoot and fix your computer when it fails to boot into their primary operating system due to software or hardware failures.
For more information about the Dell SupportAssist OS Recovery, see Dell SupportAssist OS Recovery User's Guide at www.dell.com/support.