Computer does not boot

Discussion in 'Computer Information' started by Dimetric Houston, Sep 20, 2004.

  1. Hello all.

    My neighbor's computer has a serious problem. When they turn it on, the
    screen stays black and a message appears saying

    "NTLDR is missing. Ctrl+Alt+Del to restart"

    If they hit the aforementioned buttons, the same message appears.

    They have a Hewlett Packard running WinXP.

    The only thing they could tell me was that this happened after the power
    went out one night. I didn't see a surge protector anywhere, and I don't
    know if this happened during a storm or was it just an abnormal power outage

    Is there a way to fix this?

    Dimetric Houston, Sep 20, 2004
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  2. Dimetric Houston

    w_tom Guest

    A surge protector would have done nothing for a power loss.
    In fact, a plug-in surge protector can even contribute to
    surge damage of an adjacent and powered off computer.

    If the system disk was FAT32 (verses the reliable NTFS),
    then power loss may delete files on the drive. The file NTLDR
    is missing. File can restored (copied to hard drive) by so
    many methods from system boot disks, CD-Rom, etc. Numerous
    solutions have been posted previously. But now ask what is
    defective in that system that a power loss (not a power surge)
    caused a file to be deleted. This was just another reason by
    FAT filesystem was made obsolete.
    w_tom, Sep 20, 2004
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  3. Dimetric Houston

    Plato Guest

    Plato, Sep 20, 2004
  4. Dimetric Houston

    L;ozT Guest

    ....or maybe, just maybe, there is already a floppy disk in drive A: which
    got left in the computer when it shut down. Ask them to check the floppy

    L;ozT, Sep 21, 2004
  5. Dimetric Houston

    Thor Guest

    that would result in "non system disk or disk error" not "NTLDR is missing".
    Thor, Sep 21, 2004
  6. Dimetric Houston

    mark mandel Guest

    Check out
    mark mandel, Sep 21, 2004
  7. Dimetric Houston

    Plato Guest

    Right. Your bios has no clue re: OS messages.
    Plato, Sep 21, 2004
  8. Dimetric Houston

    L;ozT Guest

    Actually, I would beg to differ. As would the author of the webpage listed
    by Mark Mandel in the same thread.

    Link :

    Specific points to note


    NTLDR is Missing.

    Related errors:

    Below are the full error messages that may be seen when the computer is

    NTLDR is Missing
    Press any key to restart

    Boot: Couldn't find NTLDR
    Please insert another disk



    1.. Computer is booting from a non-bootable source


    Computer is booting from a non-bootable source

    Many times this error is caused when the computer is attempting to boot
    from a non-bootable floppy disk or CD-ROM. First verify that no floppy
    diskette is in the computer, unless you are attempting to boot from a


    As per comments from Plato, and Thor, quite simply, you are wrong. The
    precise nature of a fault may or may not give you either of the said
    results. And the issue here is nothing whatsoever to do with the BIOS.

    In case you wondered, yes, I am a fully qualified Microsoft Certified
    Systems Engineer, and have worked full time as Systems Administrator for the
    Largest NHS Trust in Europe for the last five years, on top of a vast other
    amount of experience and study. Because of this, I happen to know something
    about this.

    No offence intended by my snottiness.


    L;ozt certainly seem to be!
    L;ozT, Sep 22, 2004
  9. Dimetric Houston

    w_tom Guest

    A program in first two disk sectors gets executed by BIOS.
    This boot program is uniquely modified both for that disk and
    for the operating system that formatted that disk. If that
    boot program does not exist, then BIOS outputs a unique
    message (from hardware manufacturer) about not finding
    bootable disks.

    If that program does exist and is for DOS based systems (ie
    Windows 9x), then the boot program looks for the files IO.SYS
    and either MSDOS.SYS or IBMDOS.SYS. These OS booting programs
    are different from the boot sector program and are next
    software to be executed. If boot program does not find these
    files only on that one disk, then this message is output:

    Non-System disk or disk error
    Replace and press any key when ready

    However if the boot sector is for NT based OS and if the
    unique parameters in that boot sector program do not find an
    NTLDR file, then this message outputs:

    BOOT: Couldn't find NTLDR

    If a boot diskette is formatted originally by NT, and if
    NTLDR is not on that diskette, then it will boot the latter
    message. If the NTLDR file is missing on hard drive and if
    the BIOS executes boot sector on hard drive, then system will
    output same message. To get this message, the boot sector
    program must have either of two problems:
    1) the boot sector program is not unique to the disk format,
    2) the boot file (NTLDR or MSDOS.SYS, etc) is not on that

    Diskettes not loaded to boot an operating system can still
    contain the boot sector program. Which message is posted can
    tell whether the diskette was formatted by DOS based or NT
    based OS. If the boot sector program is not read, then BIOS
    will output a unique message not from Microsoft. Above are
    the Microsoft error messages from the boot sector program.

    w_tom, Sep 22, 2004
  10. Dimetric Houston

    L;ozT Guest

    I appolgise for sounding rude, but may I ask, do you actually fully
    understand the content of what you posted, or have I mis-interpreted your
    reason for posting?

    .....ok. So the BIOS is involved in booting up a computer full stop.


    What I meant when I said:

    'And the issue here is nothing whatsoever to do with the BIOS.'
    <end quote>

    is not that booting up a computer, regardless of operating system or fault,
    does not rely on the BIOS.
    What I did say, I thought resonably clearly, is that the problem being had
    by Dimetric Houston, is in no way related to a problem with the bios. (ie
    the ISSUE HERE is nothing whatsoever to do with the BIOS). The BIOS, from
    the fact that it was able, after running through POST's, to 'execute a
    program in the first two disk sectors', which in turn was able to produce
    valid error message, would appear to be perfectly fine, and to have no

    As you quite rightly say, the issue is somewhere around the first two disk
    sectors, or boot loader, or bootable floppy, or corrupt files etc.. And in
    fact implies quite clearly, that THE ISSUE HERE IS (as in the case shown by
    Dimetric Houston) to do with one of the above, and in fact, NOTHING
    WHATSOEVER TO DO WITH THE BIOS. And so, the statement 'Right. Your bios has
    no clue re: OS messages' is not only in support of an incorrect statement,
    but also is completely irrelevant, and is also wrong in it's implication, as
    it implies that the message seen on screen (relating to NT Loader) is a BIOS
    message, when as you quite rightly quote <quote> Above are
    the Microsoft error messages from the boot sector program. <end quote> the
    message seen, is in fact, you guessed it, NOTHING WHATSOEVER TO DO WITH

    I can see you are perhaps intelligent and well read, but perhaps you need to
    read more carefully, and then think more about the implications of what you
    have read, as I believe you have misunderstood the statement made by myself
    in my previous post, and appear to have misunderstood the implications of
    your own post.



    L;ozT, Sep 22, 2004
  11. Dimetric Houston

    Thor Guest

    As you quite rightly say, the issue is somewhere around the first two disk
    I'll concede that it is *possible* for a floppy disk to cause the message,
    but it's VERY unlikely, in this case. If the floppy was formatted using XP,
    or was made bootable with XP, it makes a bootable floppy disk with a
    basic DOS OS, that by default, does not install, use, or call upon the
    NTDETECT.COM, or BOOT.INI files for anything. When a system attempts to boot
    from such a disk, it will not produce an NTLDR error in any case. If a
    bootable floppy with damaged startup files was used, then the error message
    would not involve NTLDR,
    because that file is not normally even used on a boot floppy created with
    XP's boot disk and formatting utility. You can *manually* create a
    specialized bootable
    floppy disk that uses NTLDR, and thus produce the message that way, by
    deliberately leaving off the NTLDR file, or damaging and corrupting it in
    some way. This is the only reason Microsoft even lists the floppy disk as a
    possible cause for the NTLDR error. But the floppy would have to have been
    specifically created with the
    appropriate boot configuration in order for the system to even call for the
    NTLDR file at all, and the system must call for that file for the error to
    even be generated. Yes it is a possibility, but is not in the realm of
    likelihood here, and the chances are extremely remote that this is the
    actual cause of the OP's problem. Otherwise, any old run-of-the-mill,
    non-bootable floppy disk left in
    the drive will simply produce "NON SYSTEM DISK or DISK ERROR", and things
    will halt there. If you do not believe me, try it out for yourself. Use XP's
    floppy formatting tool to create a bootable floppy, and then remove
    IO.SYS from it, attempt to boot from it and see what error
    message you get (invalid system disk). Or, simply put a blank formatted disk
    in the drive and then
    try booting from it (non system disk or disk error). Neither with give you
    an "NTLDR" is missing error.
    Thor, Sep 22, 2004
  12. Dimetric Houston

    w_tom Guest

    You are jumping to wild conclusions. I find your
    explanation very convoluted - especially not easily
    comprehended by the original poster. So I simplified it. I
    eliminated quotes from third parties and lay out how the boot
    process works - with error messages quoted exactly. So you
    are correct. Some diskettes can output the no NTLDR message.
    Others can output Non-system disk message if they were
    formatted originally to boot a DOS (Windows 9x) system. But
    read more carefully.

    I demonstrated in simple terms how a diskette in the system
    could cause a no NTLDR message - as you claim.

    Point is - where does each error message come from. And so
    I simplified it. I provided exact text that can come from
    each part of the booting process. I made no conclusions to
    what anyone said. Instead I cut through all the posts and
    stated exactly where each error message comes from.

    Now from basic facts posted previously (without
    conclusions), I now do the thinking for you. Dimetric says
    his error message is "NTLDR is missing. Ctrl+Alt+Del to
    restart". I do not find that error message in any two sector
    boot program. I find either of these message:
    DOS formatted disk:
    Non-System disk or disk error
    Replace and press any key when ready
    NT formatted disk:
    BOOT: Couldn't find NTLDR

    So where does Dimetric's message come from? Does it come
    from the BIOS? What is left?

    No, I did not ask nor answer that question. I simply posted
    straight facts without analysis. Please read more carefully.
    I expect others to use these facts to build conclusions such
    as: Dimetric's error message does not come from the boot
    sector program.

    Furthermore, your answers do not tell Dimetric how the
    booting process operates. Therefore you only confuse him.
    Posted also for his benefit was how booting occurs without him
    expecting to understand the many fancy buzz words you posted.
    Words such as POST used without defining them.

    It's really quite simple. The error message that Dimetric
    posted is not same as error message from boot sector program.
    Please explain the contradiction. A question I did not bother
    to ask previously because I assumed you would read more
    w_tom, Sep 22, 2004
  13. Dimetric Houston

    L;ozT Guest

    .....I can respect that, and agree that it may be unlikely even, but as my
    original post said <quote> ...or maybe, just maybe, there is already a
    floppy disk etc.....<end quote>, which as it suggest, is a 'maybe, just
    maybe' possibility, one which had not yet come up in the thread, and was
    simply meant to help someone, offering what may have been a simple solution.
    And even if it is completely wrong, it takes approximately 2 seconds to
    glance at the floppy drive and see if there is anything in it, the person
    checking needs little to no experience of even using a computer, and the
    computer doesn't even need to be turned on, so it couldn't hurt to glance.
    It was only a suggestion afterall.

    And anyway, no-where do I firmly state that it is the floppy disk, I merely
    offer this as one suggestion, I suggest (at least a few times) that <quote>
    the issue is somewhere around the first two disk sectors, or boot loader, or
    bootable floppy, or corrupt files etc <end quote>, making it quite clear
    that I think it could just as easily be one of a number of things causing
    the problem.

    But then still, my point remains, that in this instance, ie, Dimetric
    Houston's problem regarding his PC not booting up, is not related to the
    BIOS, and is in fact related in some way to hard disk/floppy disk/OS.


    L;ozT.............and tired!
    L;ozT, Sep 22, 2004
  14. Dimetric Houston

    L;ozT Guest

    Hello again.

    I didn't mean to offend you personally, I perhaps misunderstood your reason
    for posting.

    Just to answer some of your points below though:

    My original post, just a suggestion, was aimed at the original poster, and
    was nice and simple to understand. I appreciate that it is unlikely (as
    mentioned in previous post), but is still a possibility and still only a
    suggestion. The following posts (the slightly more technical ones) were not
    particularly aimed at the original poster, but in fact at the 'experts' who
    followed this post.

    As I said in the very first instance though, maybe, just maybe. If you
    check out the link supplied by Mark Mandel, you will see quite clearly that
    I am not alone in thinking a non-bootable floppy present in a drive, may
    cause the error as seen by the original poster. So much so in fact, that it
    is listed as the first possible option and thing to check (Please have a
    look at and check out point
    number 1, the first thing it suggests). We might both be completely wrong
    and no nothing, but we are really, deep down in our hearts, trying to help!

    Anyway, this is all getting a little heated, and really, I only wanted to
    maybe help someone and offer a suggestion.

    Come on guys. What happened to Free Love and all that hippy stuff. Surely
    we're here to help each other.

    Sorry if I dissed anyone.

    L;ozT .......... in a can of worms!
    L;ozT, Sep 22, 2004
  15. Dimetric Houston

    Thor Guest

    Peace! :)
    Thor, Sep 22, 2004
  16. Dimetric Houston

    L;ozT Guest

    ....and respect....... ;o)

    L;ozT, Sep 23, 2004
  17. Dimetric Houston

    w_tom Guest

    The devil is in the details. The OP has a message that
    NTLDR is missing. Ctrl+Alt+Del to restart

    Where does this message come from? Therein says why this
    problem occurs. Since a Boot Sector program is suppose to
    find and execute NTLDR, then nothing executed after the Boot
    Sector program(s) should create this message. Since this
    message is not found in any Boot Sector program I have seen,
    then there remains only one other place this message can come

    If the BIOS is a source of this message, then the BIOS must
    contain messages unique to using this computer with XP. I
    find that message from a BIOS rather unusual. However given
    that this error message can only come from the BIOS (the
    program that first executes when computer is powered on) or a
    boot sector program, then the unreasonable option appears to
    be the only possibility left.

    IOW if BIOS looked at all disks and did not even find a boot
    sector program on any disk. Therefore BIOS would be source
    of this "NTLDR is missing..." message. Maybe this failure is
    not even due to a missing NTLDR file as the error message

    Unfortunately, the OP must supply further information for
    this analysis to continue - or others must find this error
    message (NTLDR is missing...) in the boot sector of newer XP
    formatted disks.

    Where does the message "NTLDR is missing..." come from.
    Answer that question and we have have sufficient information
    to say exactly where the original failure is located.

    The Mark Mandel post in is nothing more
    than a laundry list of possible reasons. From his post, one
    could easily speculate that the NTLDR file did not find a
    BOOT.INI file and therefore NTLDR is the source of "NTLDR is
    missing..." (his Item 4). Or that the BIOS contains the
    "NTLDR is missing..." message (his Item 2, 7 , & 9).

    Again the devil is in the detail. Where does that message
    come from? That determines where the problem exists.
    w_tom, Sep 23, 2004
  18. Dimetric Houston

    Plato Guest

    "NTLDR is missing. Ctrl+Alt+Del to restart"

    There a few types of "bootdisks". The more common is the dos bootdisk
    which gets you into some version of dos. The second type of bootdisk is
    really a "startup" disk. ie you can make one for XP that will start XP
    that you may use if certain startup files are missing from C: You have
    to have had to make one in advance of your XP messing up tho.

    Perhaps that is the reason for the misunderstanding as yes, an XP
    "startup disk" that's bad can indeed give you the above message as XP is
    really trying to start. So the message comes from a Windows file, not
    from the bios.
    Plato, Sep 23, 2004
  19. Dimetric Houston

    w_tom Guest

    Yes it is a given that a floppy would be source of that
    message. But that means the Boot Sector program (on first two
    sectors of that floppy) would have to contain the message:
    NTLDR is missing. Ctrl+Alt+Del to restart

    As noted previously, bootable floppies for NT contain a
    message that read:
    Non-System disk or disk error
    Replace and press any key when ready or

    BOOT: Couldn't find NTLDR

    If that is the case - if that message is the result of
    system trying to boot from a formatted floppy, then we have
    all learned that XP is using a new Boot Sector program.

    Again, this is more information that we await from Dimetric
    or from others.
    w_tom, Sep 23, 2004
  20. Dimetric Houston

    derek / nul Guest

    I wonder why we did not see this message before NT came out?

    Its safe to say that it is not in the bios.

    PC boot procedure:-

    Check disk hardware.
    Load first sector of boot device into memory.
    Execute the code just loaded.

    NTLDR is missing comes from the program the is on the first sector of the
    device that the bios 'tried' to boot from.

    I have seen this many times when a floppy was left in a machine when the unit
    was turned off, I have even done it to myself.

    derek / nul, Sep 23, 2004
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