Advanced troubleshooting for Windows boot problems

There are several reasons why a Windows-based computer may have problems during startup. To troubleshoot boot problems, first determine in which of the following phases the computer gets stuck:

PhaseBoot ProcessBIOSUEFI
1PreBootMBR/PBR (Bootstrap Code)UEFI Firmware
2Windows Boot Manager%SystemDrive%\bootmgr\EFI\Microsoft\Boot\bootmgfw.efi
3Windows OS Loader%SystemRoot%\system32\winload.exe%SystemRoot%\system32\winload.efi
4Windows NT OS Kernel%SystemRoot%\system32\ntoskrnl.exe

1. PreBoot
The PC’s firmware initiates a Power-On Self Test (POST) and loads firmware settings. This pre-boot process ends when a valid system disk is detected. Firmware reads the master boot record (MBR), and then starts Windows Boot Manager.

2. Windows Boot Manager
Windows Boot Manager finds and starts the Windows loader (Winload.exe) on the Windows boot partition.

3. Windows operating system loader
Essential drivers required to start the Windows kernel are loaded and the kernel starts to run.

4. Windows NT OS Kernel
The kernel loads into memory the system registry hive and additional drivers that are marked as BOOT_START.

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 are not marked BOOT_START.

Here is a summary of the boot sequence, what will be seen on the display, and typical boot problems at that point in the sequence. Before starting troubleshooting, you have to understand the outline of the boot process and display status to ensure that the issue is properly identified at the beginning of the engagement.

thumbnail of boot sequence flowchart

Click to enlarge

Each phase has a different approach to troubleshooting. This article provides troubleshooting techniques for problems that occur during the first three phases.

If the computer repeatedly boots to the recovery options, run the following command at a command prompt to break the cycle:

Bcdedit /set {default} recoveryenabled no

If the F8 options don't work, run the following command:

Bcdedit /set {default} bootmenupolicy legacy

Read the rest. . .

Entire Microsoft Document - Advanced troubleshooting for Windows boot problems - Windows Client Management

Start with BIOS phase