29 Des 2012

Introduction

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Troubleshooting: NTLDR Is Missing
Tomy, S.E.
tomy.moniker@gmail.com
Introduction
Todays, many people eager to get their hands on a newly more sophisticated device that has
been introduced to the public. An up-to-the-minute technology can do various things for us. It
should come as no surprise that the computer producers continue to offer us more and more
sophisticated computer.
For some people, a newly sophisticated computer is a must, while for others the most important
thing is that the computer does its job. However, the trend is definitely on the side of those who
adore advancement for being digital. We can see a continuous trend of people choosing an
upgraded device like they select watches based on their capabilities and lifestyle choices. In
view of the fact that the government has so far done a good job of facilitating cheap laptops in
the markets to boost the number of computer user in the country, the number of computer user
nationwide is increasing significantly.
Every new technology may bring its positive and negative impacts within the quality of the
products. Thus, we should consider the appropriate troubleshooting policies that provide a best
solution for supporting computing activities.
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Sometime ago, I went to visit to my Little Uncle’s home. My Little Uncle is working in Jakarta,
as a teaching staff at the Department of Communication, Faculty of Social and Political
Sciences, University of Indonesia. He told me a story about his experience when purchasing a
new computer at one of the well-known computer shops in Jakarta.
He bought a new computer (notebook) marked Zyrex within the original specifications of Intel
Centrino Duo Processor, DDR 1230 MB, inclusive of Windows XP Professional operating
system, some open source office applications (Star Office), computer safety seal, and a mouse
pointing device.
Besides, he also bought an original scanner marked UMAX to add to the computer set.
After questioning and looking at some computers, he checked out the terms and conditions.
Upon a careful consideration, he decided to take the Zyrex and made a payment for it, and then
he brought home the computer.
At his home, he began to turn on the computer, to type some documents, and tested to play MP3
music for the first time with the computer. He was so delighted at that time as to be able to work
on with his new sophisticated computer set. After some minutes working with the computer, he
then quit the office application and shut down the computer. He tried to restart the computer,
subsequently while the Windows XP was loading; it appeared on the monitor a display as
follows:
(Cmos)
Monitoring Hardware
Verifying DMI Pool ..
NTLDR is missing …_
Press CTRL + ALT + DEL to restart
When looking at the computer’s monitor, he slightly got confused and he was taken by surprise
due to this problem. At the moment, he tried to restart the computer, but the problem remained
unchanged. And then, he immediately went back to the computer shop to report this problem. In
the computer shop, he explained the entire situation to the shop assistant.
After inspecting the computer for a time, the shop assistant was doubted and stated that they
were absolutely unsure as to the cause and the problem.
The shop assistant was firmly continuing in his opinion when they were in the negotiation,
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saying that perhaps there had been some negligence or misuse with the computer. The shop
assistant with the other men had been inspecting the computer and no one had yet found any of
the causes.
In the end of the negotiation, my Little Uncle decided to exchange the computer with a new one
that was Lenovo. He requested the computer to be included with an UMAX scanner. One day
after, when having his computer back, the same problem came back again with his Lenovo
computer in which it highlighted “NTLDR is missing…_”
He was wondering about the phenomenon and he went to find for help, asking to his friends in
the University of Indonesia. One of his friend who was a specialist in this field said that he had
ever experienced the problem of “NTLDR is missing” too. He suggested not setting up the
UMAX application on the computer.
Soon after having got the truly cause of the trouble. He did exactly as what being suggested by
his friend. Then, he returned the UMAX scanner to the shop to be probed.
Since then, such problem never happened anymore with his computer. At last, my Little Uncle
said to me that the UMAX application might have been a menace to the computer. And he also
alleged that the UMAX application contained an incorrect syntax. Thus, it could harm the
computer.
In this illustration, for instance, a syntax for the purpose of removing any temporary files
containing .tmp extension (e.g. after installation) written in Visual FoxPro is:
SET PATH TO c:/temp
z = ADIR(xarray, '*.tmp')
FOR a = 1 TO z
xfile=TRIM(xarray(a,1))
ERASE &xfile
ENDFOR
The above syntax can be rewritten in any other Object Oriented Programs such as using the
syntax of Visual C, Visual Basic, Java, and many more. Any syntax fallacies misrepresented in
this regard certainly have brought about some disadvantages to us.
Recently, I underwent such problem with my computer too, much the same as the story above,
NTLDR is missing. But, the apparent scenario transpired as follows:
 I was copying my files that are previously located in the drive C: (without being
enclosed in any folder) and,
 I then put them all in a folder in the same directory,
 When I shut down my computer and restarted it, then the “NTLDR is missing”
occurred.
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Ultimately, I concluded that NTLDR was one of the vital files of the operating system basically
existed in the drive C:. Learning from the circumstances, I understood the NTLDR system file
had a function to gain access to the drive C: at the booting time. It contained information about
the disk’s file system in the boot sector that loaded the Windows operating system.
What is NTLDR?
NTLDR (stands for NT Loader) is the boot loader for Windows NT operating system including
Windows XP and Windows Server 2003. NTLDR's OS loader includes basic functionality to
access IDE-based disks formatted for NTFS or FAT file systems, or CDFS (ISO 9660), ETFS or
UDFS in newer operating system versions. NTLDR is typically run from the primary hard disk
drive, but it can also run from portable storage devices such as a CD-ROM, USB flash drive, or
floppy disk. NTLDR can also load a non NT-based operating system given the appropriate boot
sector in a file.
NTLDR requires, at the minimum, the following two files to be on the system volume:
1. NTLDR, which contains the main boot loader itself
2. boot.ini, which contains configuration options for a boot menu.
Actually, only NTLDR is required. If boot.ini is missing, for Windows XP and 2003 machines,
NTLDR will default to C:/Windows on the first partition of the first hard drive. For Windows
NT machines, it will attempt to boot from C:/WINNT. Many desktops in the home are in this
configuration and a missing boot.ini file will simply generate an error stating it is missing, then
boot into Windows successfully.
Ntdetect.com is also used on computers that use BIOS firmware. Computers with Extensible
Firmware Interface (EFI), such as IA-64, use a method of device-detection that is not tied to the
operating system. Ntdetect.com is invoked by NTLDR, and returns the information it gathers to
NTLDR when finished, so that it can then be passed on to Ntoskrnl.exe (Windows kernel). To
pass information to the kernel for assigning each device some resources, on older hardware,
where ACPI (Advanced Configuration and Power Interface) is not supported, the BIOS takes
the responsibility (not the operating system).
On recent hardware, where ACPI is supported, Windows takes the responsibility so that the list
of found devices is handed to the kernel. In Windows Vista and later Windows OS, ntdetect.com
only supports ACPI, Hardware profiles are also no longer supported in Windows Vista.
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The information gathered by ntdetect.com is stored in the registry key
HKLM/HARDWARE/DESCRIPTION at a later stage in the boot process. Classes of hardware
detected are: Hardware identification, Hardware date & time, Bus and adapter types, SCSI
adapters, Video adapters, Keyboard, Serial and parallel communication ports, Hard drives,
Floppy disks, Mouse, Floating-point coprocessor, Industry Standard Architecture-based devices.
The boot loader phase varies by platform. Since the earlier phases are not specific to the OS, the
boot process is considered to start when the partition boot sector code is executed in real mode
and loads NTLDR for x86 or x64, and when the IA64ldr.efi EFI program is executed for IA-64
(IA64ldr).
How is the Boot process?
Basically, An NTLDR file which located in the root folder of the boot disk, is composed of two
parts. The first is the StartUp module and then followed by the OS loader (osloader.exe), both
stored within that file. When NTLDR is loaded into memory and control is first passed to StartUp
module, the CPU is operating in real mode. StartUp module's main task is to switch the processor
into protected mode, which facilitates 32-bit memory access, thus allowing it to create the initial
Interrupt descriptor table, Global Descriptor Table, page tables and enable paging. This provides
the basic operating environment on which the operating system will build. Then, StartUp module
loads and launches OS loader. If an x64 version of Windows is being booted (Windows XP
Professional x64 Edition or Windows Server 2003 x64 Editions), the CPU is switched into Long
mode, enabling 64-bit addressing.
The boot loader then reads the contents of boot.ini to locate information on the system volume. If
the boot.ini file is missing, the boot loader will attempt to locate information from the standard
installation directory. For Windows NT machines, it will attempt to boot from C:\WINNT. For
Windows XP and 2003 machines, it will boot from C:\WINDOWS.
At this point, the screen is cleared, the root directory default volume as defined in “boot.ini” is
searched for a hibernation file, “hiberfil.sys”. If this file is found and an active memory set is
found in it, the contents of the file (which will match the amount of physical memory in the
machine) are loaded into memory, and control is transferred into the Windows kernel at a point
from which hibernation can be resumed. The file is then marked as non-active, so that a crash or
other malfunction can not cause this (outdated) memory state to be re-loaded. If a state resume
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fails, the next time NTLDR runs it will ask the user whether to try resuming again or to discard the
file and proceed with normal booting.
If boot.ini contains more than one operating system entry, a boot menu is displayed to the user,
allowing the user to choose which operating system is to be loaded. If a non NT-based operating
system such as Windows 98 is selected, then NTLDR loads the associated "boot sector" file listed
in “boot.ini” and passes execution control to it. If an NT-based operating system is selected,
NTLDR runs ntdetect.com to gather basic information about the computer's hardware as reported
by the BIOS.
Afterward, NTLDR clears the screen and displays a textual progress bar (which is often not seen
on XP or 2003 systems, due to their initialization speed); Windows 2000 also displays the text
"Starting Windows..." underneath. If the user presses F8 during this phase, the advanced boot
menu is displayed, containing various special boot modes including Safe mode, with the Last
Known Good Configuration, with debugging enabled, and (in the case of Server editions)
Directory Services Restore Mode.
Once a boot mode has been selected, the booting continues if F8 was never pressed, then the
Windows kernel (Ntoskrnl.exe) and the Hardware Abstraction Layer (hal.dll) are read into
memory. If either of these files fails to load, the message "Windows could not start because the
following file was missing or corrupt" is displayed to the user, and the boot process comes to a
halt.
With the kernel in memory, boot-time device drivers are loaded (but not yet initialized).
Information on all detected hardware and Windows Services is stored in the HKLM\SYSTEM
portion of the registry, in a set of registry keys collectively called a “Control Set”. Typically two
control sets are kept, in the event that the settings contained in the currently-used one prohibit the
system from booting.
HKLM\SYSTEM contains control sets labeled ControlSet001, ControlSet002, etc., as well as
currentControlSet. During regular operation, Windows uses CurrentControlSet to read and write
information. CurrentControlSet is a reference to one of the control sets stored in the registry.
Windows picks the "real" control set being used based on the values set in the
HKLM\SYSTEM\Select (“Default” will be NTLDR or IA64ldr, If the value of the “Failed” key
matches Default, then NTLDR or IA64ldr displays an error message, indicating that the last boot
failed, and gives the user the option to try booting, anyway, or to use the “Last Known Good
Configuration”. If the user has chosen Last Known Good Configuration from the boot menu, the
control set indicated by the LastKnownGood key is used.
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The appropriate file system driver for the partition type (NTFS, FAT, or FAT32) such as ATA,
SCSI, file system filter manager, etc., and which the Windows installation resides on is also
loaded. Control is then passed from NTLDR or IA64ldr to the kernel. At this time, Windows NT
shows the blue screen displaying number of CPUs and the amount of memory installed, whilst
Windows 2000, XP and 2003 switch into a graphical display mode to display the Windows logo,
unless the /noguiboot or /sos switches are present in boot.ini
In Windows Vista and Windows Server 2008, NTLDR was replaced. The boot loader
functionality is instead provided by two new components: winload.exe and the Windows Boot
Manager.
Conclusion
Upon the pinpoint analysis, I did not lose my wit. I was challenged to overcome this situation, I
much thought of anything to work around it. I attempted to carry out a personal troubleshooting
experiment by reinstalling the Windows operating system, though I could not access the drive
C: at that time.
At the point, I took the following steps, and it really worked well. However, the operating
system was incorrigible, at least, the data in the drive C: still could be secured. You could also
adopt this troubleshooting to your computer whenever you got the problem of “NTLDR is
missing”, that are:
􀁸 Open the CD ROM drive,
􀁸 Insert the Windows Installation CD,
􀁸 Press CTRL + ALT + DEL to restart the computer,
􀁸 Press F9 to select any boot devices,
􀁸 Boot the computer from the CD ROM (in order to install Windows).
􀁸 When the set up is loading Windows, you must select: Leave the current system file
intact,
􀁸 Upon the License, Terms, & Condition, then press F8: I Agree.
Afterward, the monitor will be seen in this way:
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Windows XP Professional Set up
Set up is copying files…
Set up is rebooting Windows…
Then, just continue with the Windows installation wizard until finish. It takes no more than one
hour to finish installing the Windows operating system.
In addition, I want to suggest you to secure the system files on Windows, to prevent an
unintentionally deletion of the system files:
􀁸 Click Start → My Computer → Tools → Folder Options:
􀁸 Click on the Hidden Files and Folders → Click on the Do not show hidden files and
folders.
􀁸 Click on the Hide protected operating system files (Recommended).
Picture 1. Folder Options
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From these ingenious solutions, I would like to share my valuable computing experience
through this functional guideline to everyone and also remind you to be careful when organizing
files in your computer. In short, if the file you are copying, moving, renaming, or deleting is the
system file, when you ignore it, then, perhaps a serious problem can arise with your computer
either it affects any computer softwares or hardwares as Bill Gates has ever stated to us in his
book “The Road Ahead” that each computer knows something about you, but no computer
knows everything.
References
http://channel9.msdn.com/ShowPost.aspx?PostID=73995 (Windows, NT Object Manager)
http://www.microsoft.com/technet/prodtechnol/winxppro/reskit/c29621675.mspx
("Troubleshooting the Startup Process". Windows XP Resource Kit. Microsoft Technet)
http://www.windowsitlibrary.com/Content/169/01/31.html
Mark Minasi, John Enck. "Troubleshooting NT Boot Failures". Administrator's Survival Guide:
System Management and Security. Windows IT Library.
About The Writer
About the writer
Tomy, S.E. is a researcher and writer of the Information System at the
Faculty of Management of Sekolah Tinggi Ilmu Ekonomi Indonesia,
Pontianak. One of his computing books published by PT. Elexmedia
Komputindo, is titled “Tip dan Trik Profesional MySQL5”.
He can be reached at tomy.moniker@gmail.com

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