The kernel passes control to the session manager process (Smss.exe) which initializes the system session, and loads and starts the devices and drivers that aren't marked BOOT_START. Windows NT OS Kernel: The kernel loads into memory the system registry hive and other drivers that are marked as BOOT_START. Windows operating system loader: Essential drivers required to start the Windows kernel are loaded and the kernel starts to run. Windows Boot Manager: Windows Boot Manager finds and starts the Windows loader (Winload.exe) on the Windows boot partition. Firmware reads the master boot record (MBR), and then starts Windows Boot Manager. 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.