SuSE: How to restore a windows boot loader to MBR
R Kannan
I had installed SuSE 9.0 on a laptop which originally had Windows XP and
am dual booting with GRUB on MBR. I am presuming that SUSE installer had
just moved the windows boot loader to the Windows (NTFS) partition. I
would like to remove SuSE installation. Can I just boot into SuSE and
use 'Restore MBR from hard disk' under 'Reset' dropdown in Yast Boot
Loader Set up to do that safely? According to the user manual, the MBR
saved on the hard disk will be written back when I do that. Or do I need
to use Windows XP install disk to do it?
TIA
Poly-poly man
Try to restore the thing. If that fails, use (if you have it) the
windows emergency boot disk, or the cd and reinstate the loader. No idea
how, try a faq somewhere online.
poly-p man
Chris
Boot windows into a recovery console (from the install CD I
think) and issue the fixmbr command. Grub will now be
removed from the primary HD on your machine. Suse will still
be there, but accessible only with a boot CD.
HTH
Chris.
iforone
I'm not sure why , but most everyone lately fails to mention the
complications that arise from using the HDD manu DOO software to
partition and format the HDD in question (especially in light of the
48bitLBA issues)....if one uses FIXBOOT and FIXMBR, after having used
any HDD manu DDO, they will surely munge their MBR.
just a notation :-)
iforone
Chris
I don't understand what you mean. At what point did the OP
say they used 'HDD manu DDO software' to partition the HD?
What 48bit LBA issues do you mean?
Clarification of the above plus how that would result in a
munged MBR would be most useful.
iforone
hi;
the OP never did - and in the OP's particular scenario, i'm not sure
what exactly is the correct course of action -- and my comments are
merely meant as 'cautionary', or a "please take into account all the
possibilities" type of comment..not accusatory of anyone in any way at
all.
Note also the OP is using a Laptop - which are (most times) OEM
pre-loaded with the windoze OS, and many times contain a small FAT
'hidden' backup partition (OS restore image) in and of themselves on
the HDD...some come with Restore CDs, and still others require you to
make your own restore CDs from the hidden partition.
Now, if (as i like to do) the OP originally wiped the HDD as soon as
s/he bought it an installed a Retail (or even another diff OEM) version
of XP, then s/he likely setup (partitioned and formatted) the HDD
themselves using XP's built-in Disk utilites (DISKPART, FORMAT, etc).
Speaking of Laptops -- my mistake, in that it's highly unlikly the HDD
is a 'large' HDD (over 137GB) -- so my DDO software warning can
generally be ignored in this instance. However, the Laptop manu OEM,
may still have created a 'funky' partitioning scheme on the HDD. Most
cheaper Dell Dimensions do this, and the actual 'Boot' partition is the
2nd on the HDD, not the 1st, which is usually reserved for Dell's
'hidden' FAT16 (~32MB) diagnostic tools. Many OEMs carry out this
'type' of scheme.
Many people also use the HDD manu "utilities" (EZ-DRIVE, MAXBLAST,
ONTRACK, etc) - not to mention 3rd party partitioning tools such as
Partition Magic -- either to 'clone' from an older HDD to a new HDD -
and some use the DDO software to overcome BIOS limitations of HDDs
larger than 137GB (48bitLBA issues, requiring atleast windoze 2KSP3 or
XPSP1)...and many don't even realize that by using DDO, they've created
'custom' partition table signature bytes.
Fortunately, atleast when using FIXMBR, one is presented with a
"warning" - IF the command finds a 'nonstandard partition table
signature' -- then atleast the User is presented with the option to
continue or not at that point.
here's some related text;
=============================================
http://cquirke.mvps.org/multboot.htm
Caveats
That's how the standard Master Boot Record (MBR) works, and as this
exists at the system rather than Operating System (OS) level, it's not
supposed to be deviated from this behavior by any OS.
But because OSs assume this code to be standard, they may replace it
with the standard code. This would break deviations from the standard
MBR code and partition table structure, such as the following:
* Boot managers residing in MBR
* Dynamic Drive Overlay (DDO) driver
* Boot code viruses that infect the MBR
If you need non-standard code here (e.g. a DDO to override an old
BIOS's disk services that can't cope with "large" hard drives, or a
boot manager that lives in the MBR) then you need a way to restore this
should anything corrupt the MBR or overwrite it with the standard MBR
code.
Also, remember that other boot devices (CDR, diskettes, USB flash
drives, other physical hard drives) won't process this "special" code
unless the same logic is integrated into the boot-up code of these
devices
=============================================
and while the info here is somewhat older and perhpas a bit defunct -
it goes to my point;
http://www.win.tue.nl/~aeb/partitions/partition_types-1.html
In Ending;
SuSE (and/or grub) seem to have the situation well in hand and seems to
have 'preserved' whatever was there prior to installation...and is
offering to replace it. I hope it works out easily for the OP. All I
can say for sure is Backup, Backup, Backup your important Data ;-)
Chris
[snip more useful info]
> In Ending;
> SuSE (and/or grub) seem to have the situation well in hand and seems to
> have 'preserved' whatever was there prior to installation...and is
> offering to replace it. I hope it works out easily for the OP. All I
> can say for sure is Backup, Backup, Backup your important Data ;-)
>
Thanks for the well-written and detailed response :-) Most
useful to know...