Files load at different stages of Startup:

Files load at different stages of Startup:

Boot Time:

File	From
NTLDR	C:\
Boot.ini	C:\
NTDETECT.COM	C:\

Kernel Time:

File	From
NTOSKERNEL.EXE	c:\windows\system32\
HAL.DLL	c:\windows\system32\
System	c:\windows\system32\
Drivers	c:\windows\system32\Drivers

Preboot Sequence:

ü  POST, detection of hardware by BIOS

ü  BIOS locates boot device then loads MBR

ü  MBR scans partition table for active partition and executes it.

ü  Loading of NTLDR, which then loads the OS.

Problems related to preboot sequence:

1. If BIOS is unable to detected hard-disk during POST, startup fails and an error message is given.

Possible cause:

                                i.            Hard-disk is ruined.

                              ii.            SATA cables not connected properly.

                            iii.            Power cable of hard-disk is not connected.

2. Corrupt MBR- If MBR is corrupt startup fails giving an error message.

Possible cause:

                                i.            Virus infection

                              ii.            Improper Installation

Can be repaired by Recovery Console

3. USB disk plugged- On most computers BIOS is configured to first boot from floppy or USB if found, than from HDD. Hence startup fails stating that no OS found on the disk.

Possible cause:

                                i.            Incorrect BIOS setting

                              ii.            Hard-disk failed

            Can be repaired by correcting BIOS setting or changing hard-disk which ever applicable.

Problems related to boot sequence:

If NTLDR, boot.ini or NTDETECT.COM is missing or corrupt hence startup fails.

Possible cause:

1. Virus Infection
2. Improper Installation

Can be repaired by Recovery Console

NOTE: If NTDETECT.COM file is corrupt it means there is a hardware or hardware driver issue.

            Possible cause:

                                i.            A newly added hardware device printer etc.

                              ii.            A new driver update for old hardware device.

Repair using Recovery Console:

v  Insert XP CD

v  Boot from CD

v  When prompted press R to repair existing OS

v  When prompted press C to start Recovery Console.

v  Now you will see a command prompt.

v  Type “help” and press enter for various commands.

v  Important Commands:

                                                        i.            fixmbr : To repair corrupt mbr

                                                      ii.            fixboot : To write a new partition boot sector onto the system partition.