OS BOOT FILES

DOS Boot up Sequence

IO.SYS – A binary file that provides basic input/output interface between the ROM BIOS and the Hardware
MSDOS.SYS – A binary file considered to be the core of the DOS operating system
CONFIG.SYS – A text file used to load drivers and memory managers and also use to configure the system to the user’s needs
COMMAND.COM – DOS user interface loads the command prompt which interprets DOS commands
AUTOEXEC.BAT – A text file that contains setting up display settings, environment variables and routines

Win 9X Boot up Files




IO.SYS - I/O files use to communicate with the BIOS
MSDOS.SYS - Loads OS into memory (Also use to configure boot files in windows 9x)
SYSTEM.DAT and USER.DAT - system and user settings (REGEDIT)
CONFIG.SYS - loads device drivers for backwards compatibility
AUTOEXEC.BAT - sets system environment use for backwards compatibility
WIN.COM - Initiates the Windows 9x protected load phase
SYSTEM.INI - use to configure 16-bit windows drivers and critical files
WIN.INI- sets 16-bit windows environment
VxD - loads windows virtual device drivers


Windows XP Key Boot Files

NTLDR – Found in the MBR this file boots up the Windows 2K/XP operating system
BOOT.INI - is text file that lists the available OS found and tells the NTLDR where to find boot partition
BOOTSECT.DOS – Locates the IO.SYS file so you can start another OS in a dual boot environment
NTDETECT.COM – Loads into protected mode and detects the installed hardware on your system
NTBOOTDD.SYS - On a system with a SCSI boot device, this file is used to recognize and load the SCSI boot partition.
NTOSKRNL.EXE- Windows 2000 Core Files
WIN.COM - Windows 2K/XP command file
HAL.DLL - Hardware Abstraction layer of Windows 2K/XP

Windows Vista/7/8 Key Boot Files

BOOTMGR – Found in the MBR this file boots up the Windows operating system
BCD (Boot Configuration Data) - is text file that lists the available OS found and tells the BOOTMGR where to find boot partition
WINLOAD.EXE- Loads the Windows Interface
NTOSKRNL.EXE- Windows Vista/7 Core Files
WIN.COM - Windows Vista/7 command file
HAL.DLL - Hardware Abstraction layer of Windows Vista/7