Here’s the brief description of Windows Server 2008 Boot process.
- System is powered ON
- The CMOS loads the BIOS and then runs POST
- Looks for the MBR on the bootable device
- Through the MBR the boot sector is located and the BOOTMGR is loaded
- BOOTMGR looks for active partition
- BOOTMGR reads the BCD file from the \boot directory on the active partition
- The BCD (boot configuration database) contains various configuration parameters( this information was previously stored in the boot.ini)
- BOOTMGR transfer control to the Windows Loader (winload.exe) or winresume.exe in case the system was hibernated.
- Winloader loads drivers that are set to start at boot and then transfers the control to the windows kernel.
STEP 1:
The first step is to see what hardware is available and its condition by using the power-on self
test (POST) routine. Next, BIOS executes the initial program load (IPL), which locates the
boot device and, if the device is a hard disk, the master boot record (MBR) is read from
the first sector on the disk. Otherwise, the equivalent information is obtained from the
boot device. From this information, partition information is obtained, the boot sector is
read, and the Windows Boot Manager (Bootmgr.exe) is started. On the screen, you see the
memory check, the identification of hardware, and the search for a boot device.
STEP 2:
Windows Boot Manager reads the boot configuration data (BCD) and, if there is
more than one boot partition, asks the user to choose a partition and its OS. If a choice is
not made before the timeout, the default partition and OS is loaded. If you are booting
Windows Server 2008, the Windows Boot Loader (Winload.exe) is started. If you have
more than one hardware profile, you are given the option of pressing the spacebar to
select the hardware profile you want to use, for example, if you have a laptop that you
sometimes use with a docking station. If you press the spacebar , you can choose the
hardware profile you want; otherwise, the default profile is used.