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Old 05-06-2004, 10:01 AM   #1
WhatsHisName
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WinXP fixmbr = DOS fdisk /mbr


With regards to addressing dual boot problems, have you ever wondered whether XP fixmbr and dos fdisk /mbr did the same thing? Here is an interesting tidbit from the microsoft windows xp support site (specifically, from the Microsoft Windows XP Professional Resource Kit Documentation):

http://www.microsoft.com/resources/d...d_tro_oxhc.asp

“...The Recovery Console, a troubleshooting tool in Windows XP Professional, offers a feature called Fixmbr. However, it functions identically to the Fdisk /mbr command, replacing only the master boot code and not affecting the partition table...”

For more information about fdisk /mbr, see:

http://support.microsoft.com/default...kb;en-us;69013

For more information about fixmbr, see:

http://www.microsoft.com/windowsxp/h...ons_fixmbr.asp

Since links sometimes change over time, just search microsoft support for “fixmbr” and/or “fdisk /mbr” to find these links in the future.
 
Old 05-06-2004, 10:26 AM   #2
RockmanExe
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Re: WinXP fixmbr = DOS fdisk /mbr

Quote:
Originally posted by WhatsHisName

“...The Recovery Console, a troubleshooting tool in Windows XP Professional, offers a feature called Fixmbr. However, it functions identically to the Fdisk /mbr command, replacing only the master boot code and not

I think it says that works identically (has the same result), but i reckon you can't use one as the replace of the other. i.e. xp' recovery console to restore win98 mbr. I remember how some guys screwed win95' mbr by using winME's boot disk and fdisk /mbr


Cheers!!
 
Old 05-06-2004, 11:28 AM   #3
WhatsHisName
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RockmanExe: You are probably thinking about the XP recovery utility “fixboot”, which is OS specific.

The beginning of the boot process is fairly generic. Once the system POSTs, control is passed to the Master Boot Code within the Master Boot Record (MBR). That’s what fdisk /mbr replaces and also what gets replaced by Grub stage1. When the Master Boot Code is executed, control is passed to the targeted partition’s Partition Boot Sector, sometimes called the first sector of the boot partition. In the case of XP, this triggers the call for the NT Loader (NTLDR). For windows-type systems, the Master Boot Code in very generic. It basically says “load and execute the first 512 bytes of the boot partition”. It’s what happens next that is OS specific.

XP “fixboot” rewrites the Partition Boot Sector with information specific to XP, just like Grub rewrites the Partition Boot Sector with Grub specific information.

I have personally used dos fdisk /mbr dozens of times on dual boot XP/linux systems without a problem. It also works on Win95, Win98 and WinNT4.0. I have never tried it on WinME or Win2K, but I assume it would work, since Win98SE/WinME and Win2K/NT4 are kissing cousins.

My post will surely be followed by several “fdisk /mbr screwed my disk” comments. My questions in response are “what else did you do before trying fdisk /mbr?” (i.e., what else was screwed up or what else did you screw up) and “did you read the warnings about using fdisk /mbr?” (i.e., for safety, only have one drive connected when you run fdisk /mbr).

To pirate a slogan, “Fdisk doesn’t kill drives, people kill drives”.
 
Old 05-06-2004, 05:00 PM   #4
RockmanExe
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Hey! i never said I screwed the disk ,
in fact was some guys next to me who tried to 'restore' (don't know why since it was working fine) the mbr with a winME boot disk they had by hand. Strange things happen: the hard drive (only hard drive) never boot up again, even thought it was a healthy HD.
i've not worked on a win9x lastly only w2k and xps and indeed i can mix recovery consoles from both systems to aid each other, but they're very close friends as you said

Regards
 
Old 05-06-2004, 05:53 PM   #5
WhatsHisName
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Never tried to do this intentionally, but if you hide all of the partitions (i.e., none are set as “active”) and run fdisk /mbr, the system would probably appear to be unbootable. Resetting one partition as active (and possibly running fdisk /mbr again) would awaken Sleeping Beauty.

Accidentally hiding partitions can be a problem when you are running partition manipulation programs (i.e., fdisk, parted, PartitionMagic) and something unexpected goes wrong. It’s easy to fix, but hard for the “partition newbie” to figure out. I know, it’s happened to me a long time ago running PartitionMagic 6 under WinNT4!
 
  


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