Materi IlmuKomputer.Com · Web viewAt his home, he began to turn on the computer, to type some...

Troubleshooting: NTLDR Is Missing

Tomy, [email protected]

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

Komunitas eLearning IlmuKomputer.ComCopyright © 2003-2007 IlmuKomputer.Com

1

Lisensi Dokumen:Copyright © 2003-2008IlmuKomputer.ComSeluruh dokumen di IlmuKomputer.Com dapat digunakan, dimodifikasi dan disebarkan secara bebas untuk tujuan bukan komersial (nonprofit), dengan syarat tidak menghapus atau merubah atribut penulis dan pernyataan copyright yang disertakan dalam setiap dokumen. Tidak diperbolehkan melakukan penulisan ulang, kecuali mendapatkan ijin terlebih dahulu dari IlmuKomputer.Com.

solution for supporting computing activities.

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


2

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, 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:/tempz = ADIR(xarray, '*.tmp')FOR a = 1 TO z xfile=TRIM(xarray(a,1))ERASE &xfileENDFOR

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,Komunitas eLearning IlmuKomputer.ComCopyright © 2003-2007 IlmuKomputer.Com

3

When I shut down my computer and restarted it, then the “NTLDR is missing” occurred.

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 Komunitas eLearning IlmuKomputer.ComCopyright © 2003-2007 IlmuKomputer.Com

4

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.

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


5

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 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


6

http://en.wikipedia.org/wiki/Hal.dll

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.

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:


7

Windows XP Professional Set upSet 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).


8

Picture 1. Folder Options

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


9

("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 [email protected]


10

mailto:[email protected]

Materi IlmuKomputer.Com · Web viewAt his home, he began to turn on the computer, to type some...

Documents

Transcript of Materi IlmuKomputer.Com · Web viewAt his home, he began to turn on the computer, to type some...