Boot Process & Recovery Tools

What does firmware do when a computer starts?

Runs POST to verify system components are present and functioning correctly, identifies a boot device, and passes control to the operating system's boot loader process

What does POST verify?

System components are present and functioning correctly

In a legacy BIOS boot, what does the firmware read from the boot device first?

Master boot record (MBR) in the first sector of the disk

In legacy BIOS boot, what does the MBR identify?

The boot sector for the partition marked as active

In Windows legacy BIOS boot, what loads the boot manager, and what is the boot manager file?

The boot sector; BOOTMGR.EXE

What does BOOTMGR.EXE read, and what does that file identify?

Boot configuration data (BCD) file; operating systems installed on the computer

Where are BOOTMGR and the BCD normally installed?

Hidden System Reserved partition

If there is only a single Windows installation, what does the boot manager load and where is it stored?

WINLOAD.EXE stored in the system root folder on the boot partition

If there is more than one OS installation, what does the boot manager do?

Shows a boot menu allowing the user to select the installation to boot

What does WINLOAD load before control is passed to the kernel?

NTOSKRNL.EXE, HAL.DLL, and boot device drivers

After the kernel initializes and starts loading the required processes, which process waits for the user to authenticate?

WINLOGON

In UEFI boot mode, what does the firmware read after POST?

GUID partition table (GPT) on the boot device

What does the GPT identify in UEFI boot mode?

EFI System Partition

What does the EFI System Partition contain?

EFI boot manager and the BCD

Under what path does each Windows installation have a subfolder in UEFI boot mode, and what does it contain?

\EFI\Microsoft\ ; a BCD and BOOTMGFW.EFI

What does BOOTMGFW.EFI use the BCD for?

To identify whether to show a boot menu and to find the location of WINLOAD.EFI

After BOOTMGFW.EFI finds WINLOAD.EFI, how does the boot process continue?

Windows boot loader continues by loading the kernel, as described previously

What do you need to use to troubleshoot boot issues?

options and recovery tools to access an environment in which to run tests and attempt fixes

What does the Advanced Boot Options menu allow?

selection of different startup modes for troubleshooting

When are startup options displayed automatically?

if the system cannot start the OS

How do you access startup options with BIOS boot?

press F8 before the OS loads

How do you access boot options with UEFI?

hold the SHIFT key when selecting Restart from the Power menu on the lock screen

How do you access Advanced Boot Options in Windows 11?

Settings -> System -> Recovery -> Advanced startup -> Restart Now

What path opens Startup Settings from the first Choose an option screen?

Troubleshoot -> Advanced options -> Startup Settings -> Restart

Which key selects Safe Mode?

F4

What does Safe Mode load?

only basic drivers and services required to start the system

What can you boot from if you cannot boot the computer or access startup options from the local installation?

product media, a repair disk, or a recovery partition

What might you have to configure in BIOS or UEFI setup?

recovery media as the priority boot device

Which option can fix damaged boot files in the recovery environment?

Startup Repair

Which commands can you run from the Windows Recovery Environment command prompt?

diskpart, sfc, chkdsk, bootrec, bcdedit, regedit