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False Dual Boot Option During POST

Discussion in 'Windows XP' started by skaler2k, 2005/10/01.

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  1. 2005/10/02
    PeteC

    PeteC SuperGeek Staff

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    Yes - it's getting very deep :D Fascinating though it is I must hold fire for the moment. It's getting late over here and my brain's feeling the effects of a long day and is not conducive to 'deep thought' :)

    Yes, I reformatted the partition and reinstalled. One thing to bear in mind - Vista is different from XP in many ways and is only beta 1 at present - may be that's where the bug is.
     
    PeteC,
    #21
  2. 2005/10/02
    Christer

    Christer Geek Member Staff

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    sparrow,

    Your assumption is corect in my case. The file system was NTFS in all cases.

    On FAT32, when using a Win9X start disk and FDISK to partition, after exiting FDISK, I always ran the command fdisk /mbr. I believed that was the command rebuilding the MBR and on an empty hard disk, the MBR would be wiped clean. Is that incorrect?

    Christer

    Edited:

    I didn't see the posts after #15 before posting!
     
    Christer,
    #22


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  4. 2005/10/02
    Christer

    Christer Geek Member Staff

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    sparrow,

    DELPART is a Microsoft utility from the NT days. It was devised to get rid of any non-DOS partition by completely wiping partitons, boot records and master boot records.

    Petec,

    I read somewhere at Microsoft that Vista doesn't use a installer like we're used to. It said something about an "image install ".

    Could that have a bearing on this?

    Christer
     
    Christer,
    #23
  5. 2005/10/02
    sparrow

    sparrow Inactive

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    Hi Christer,

    Can't hurt anything, but isn't necessary. Sometimes helps if the disk refuses to boot because its function is to point to the address that has code for the next operation in the boot sequence, which is often the start of the OS.

    Not familiar with DELPART but sounds like it does the same as low level format but just to the system areas?
     
    Last edited: 2005/10/02
    sparrow,
    #24
  6. 2005/10/02
    PeteC

    PeteC SuperGeek Staff

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    Christer
    Well the CD which I burnt from a downloaded DVD ISO image looks very much like an XP install CD in terms of structure. One notable difference is that there are no *.cab files but a new compressed file type *.wim. There are a few other things which may be relevant, but I feel that I am not in a position to reveal those. Sorry to be a little mysterious, but I am bound by a Non Disclosure Agreement with MS.
     
    PeteC,
    #25
  7. 2005/10/02
    sparrow

    sparrow Inactive

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    Christer,

    Hi. found MS's definition of:
    DELPART.EXE Command-line utility; FDISK that can recognize NTFS
    partition and remove it.
    But can't download it any more unless ir's on the web somewhere else. MS says just delete NTFS partitions with the install disk. :)
    It's just fdisk on steroids.
     
    sparrow,
    #26
  8. 2005/10/02
    Christer

    Christer Geek Member Staff

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    PeteC,

    Well, I didn't intend to extact any "classified information ". I only tried to find a difference between XP and Vista that may have a bearing.

    However, most privileged people "leak" when answering innocent questions ...... :D ...... !

    sparrow,
    I quote from a few of my own posts:

    I have searched, trying to find that information again but it may be my own conclusions based on usage. The mind is a strange place!

    Click the link in post #3!

    Christer
     
    Last edited: 2005/10/02
    Christer,
    #27
  9. 2005/10/03
    sparrow

    sparrow Inactive

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    Thanks Christer,

    Got it. Missed the URL earlier, and google must have had the reference buried in the million hits somewhere. :D

    Actually, have never tried to delete an NTFS, so didn't realize fdisk couldn't do it; mine (on a win98 startup disk) does recognize NTFS partitions by name. Like I've said, there's no such thing as an expert, particularly when one's been retired for some years!
     
    sparrow,
    #28
  10. 2005/10/03
    Christer

    Christer Geek Member Staff

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    Strange, when I go Google on 'delpart', that web page is the first hit.

    Like we say about pilots, 'the experts are those who realize that they can't do everything' ...... :cool: ...... !

    Christer
     
    Christer,
    #29
  11. 2005/10/03
    oshwyn5

    oshwyn5 Inactive

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    My example would be if you have previously installed linux on a system. Then you try to wipe the partitions and install XP . It just won't work unless you use a linux FDISK first to wipe the partitions and MBR. It really depends on the partitioning tools used, both initially and to reparition.
     
    oshwyn5,
    #30
  12. 2005/10/04
    sparrow

    sparrow Inactive

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    That is not a direct answer, because we're discussing DOS/Windows. You seem to contradict yourself; "use a linux FDISK first to wipe the partitions and MBR. " is opposite your first claim.

    I've not had occasion to replace linux with XP, but did something similar a few times over the years with slakware, red hat, and mandrake, and don't recall that DOS fdisk ever failed to remove partitions.

    The MBR is another animal. Don't see why removing a partition changes the MBR; rather it's making a partition and installing an OS that should change the MBR because it changes the boot information, or pointer. Would think XP would work like DOS in the same situation, but maybe not, considering the current subject. Actually, if partitioning wiped the MBR, it would make the disk unbootable.

    However, it's 'well known' that each fdisk makes different flavors of partitions, so that you "can't" partition with DOS for use by linux, or with linux for use with DOS, though think it's been done.
     
    sparrow,
    #31
  13. 2005/10/07
    sparrow

    sparrow Inactive

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    oshwyn5

    Did some experimenting and found no problem having XP remove a linux partition in Disk Manager.

    No problem with win98 fdisk either; one of the options is "remove Non-DOS partition ". Recognizes NTFS by name but not linux. Makes one wonder about how many versions of fdisk there may be; believe I've seen a list on MS web site.

    Found out, again?, that restoring a partion with ghost doesn't restore the MBR; have to do an fdisk /mbr also, to eliminate GRUB, the linux multiboot manager, which isn't removed when the linux partition is removed and gets very confused.

    More information to follow. Takes time, between other projects. :D
     
    sparrow,
    #32
  14. 2005/10/07
    sparrow

    sparrow Inactive

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    oshwyn5

    I just finished testing the installation of XP, and XP64 trial and both installers had no problem removing a linux partition and both wrote a new MBR for the new OS.

    You obviously haven't done what you say, because you're too smart to be unable to do it.
     
    sparrow,
    #33
  15. 2005/10/07
    sparrow

    sparrow Inactive

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    Christer

    From Christer
    All I can think is that the XP installer read info in the previous MBR, which is not removed along with the partitions, and found evidence of the previous OS and is programmed erroneously to keep the information, as in the current case. It's a bug.
     
    sparrow,
    #34
  16. 2005/10/09
    Christer

    Christer Geek Member Staff

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    Hi sparrow!

    That's my conclusion too. The only location to find evidence of a previous installation in my example was in the MBR.

    Well, I'm not sure Microsoft would call it a bug ...... :eek: ...... but a feature!

    As I understand it, the XP installer is designed to automatically create a multiboot if an operating system is detetcted on the computer. It seems like it's reading the MBR but not checking if it really is there.

    Christer
     
    Christer,
    #35
  17. 2005/10/09
    sparrow

    sparrow Inactive

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    Hi Christer,

    Agreed. But it shouldn't happen, right?

    Have gone into this as far as ability allows. Find that
    That's lots of space and maybe things get messy? Without more knowledge of NTFS, we're helpless to know what's going on.

    MS: This page
     
    sparrow,
    #36
  18. 2005/10/10
    Christer

    Christer Geek Member Staff

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    Hi sparrow!

    There is a regular visitor at RADIFIED who has great knowledge about disks, partitions, volumes and anything related. I will post over there, asking him to have a look into our discussion.

    Christer
     
    Christer,
    #37
  19. 2005/10/10
    Christer

    Christer Geek Member Staff

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    Christer,
    #38
  20. 2005/10/11
    PeteC

    PeteC SuperGeek Staff

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    Thanks, Christer :)

    That's a great explanation over at Radified. Now all I have to do is remember it :)
     
    PeteC,
    #39
  21. 2005/10/11
    sparrow

    sparrow Inactive

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    Hi Christer,

    Thanks. That's very good! However,
    even though the place where the 'no longer extant' OS is remembered may be different, it wouldn't have been difficult for the programmer to re-call the subroutine that identified it, to correct the error. That would improve the logic of the installation program.
     
    sparrow,
    #40
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