Windows 2008 BCD Changes system startup mode

Many new features are introduced into Windows Server 2008, including the new boot mode. Starting an operating system is a critical step for a computer, and the normal start-up of a Microsoft Windows operating system that currently occupies a large number of desktop computer market areas affects all users who use the Microsoft Windows operating system. As we all know, Windows boot way through many changes, basically for each generation of Windows operating system, Windows to start the way to occur a change. Windows Server 2008, as the 6th-generation Windows operating system, has changed its startup mode again.

In Windows Server 2008 and Windows Vista, either early boot from pure DOS mode or the ntldr+ntdetect.com boot of Windows 2000/xp/server 2003 now, have been abandoned. A component called the Boot Manager replaces the ntldr+ntdetect.com boot approach and becomes the Windows boot approach used by Microsoft in Windows Server 2008 and Windows Vista.

In Windows Server 2008 and Windows Vista, Microsoft introduced a new boot loader architecture, Windows boot Manager (Bootmgr.exe). Unlike Ntldr, which relies heavily on hardware, the new architecture in Windows Server 2008 enables complete hardware independence and seamless integration with a variety of operating systems, making the Windows Server 2008 boot/boot process faster and more secure. Also, transfer the content managed by Boot.ini in the previous Windows system to the new boot Configuration data (BCD: Startup settings), and of course, the new startup options Editing Tool, BCDEdit (BCDEdit.exe), to Manage startup settings. For machines with Windows Server 2008 installed, Microsoft modifies the boot sector of the active primary partition (Windows Installer writes MBR content to the first sector of the disk) and replaces the contents of the original boot sector with the new boot sector content. Classic error message: "Ntldr is missing" will be replaced by "Bootmgr is missing".

What is a BCD store

The boot Configuration Data (BCD) is used to store startup configuration parameters and to control how Windows Server 2008 and Windows Vista systems are started. These parameters are stored in the Boot.ini file in the previous operating system (in the BIOS based operating system) or on nonvolatile RAM (NVRAM). Users can use the Bcdedit.exe command-line tool to control the operation of the Windows®code in the operating system environment, thus enabling the addition, deletion, editing, and loading of the BDC store.

The Bcdedit.exe tool is stored in the \Windows\System32 directory of Windows Vista partitions. For BIOS based operating systems, the registry files for BCD are stored in the \BOOT\BCD directory of the primary partition. For the EFI based operating system, the BCD registration file is positioned on the EFI system partition. Only users with administrator privileges can modify the BCD.

The C:\Boot\BCD file is the entire BCD database. When Windows Vista runs, this file cannot be deleted or renamed, because the system has been hogging it. If the user deletes this file and the boot Manager is installed, the user's system will not be able to boot because the boot manger cannot find the appropriate BCD data file to use.

Why boot.ini want to upgrade to BCD?

BCD was born primarily to describe a new and improved mechanism for initiating configuration data. With the development of the new firmware model (for example, the Extended Firmware Interface (EFI)), users need to provide an extensible generic interface for the underlying firmware abstraction. This new design will provide the necessary support for many of the new features of Windows Server 2008 and Windows Vista (for example, starting the recovery tool and multiple user installation snapshots).