This pre-boot process ends when a valid system disk is detected. PreBoot: The PC's firmware initiates a power-on self test (POST) and loads firmware settings. To troubleshoot boot problems, first determine in which of the following phases the computer gets stuck: Phase There are several reasons why a Windows-based computer may have problems during startup. If you're looking for more general information about recovery options, see Recovery options in Windows 10. This article is intended for use by support agents and IT professionals.
