MBR blown away

[Ken Stevenson]

Peter wrote:
> --- Jerry McAllister <jerrymc at clunix.cl.msu.edu> wrote:
> 
>>>
>>> --- Jerry McAllister <jerrymc at clunix.cl.msu.edu> wrote:
>>>
> 
>>>>> I added a slice to a single hard drive dual-boot (windows) system
>> and
>>>> now
>>>>> I guess that scrambled my MBR.  I get three options from the
>> FreeBSD
>>>> (5.4)
>>>>> boot manager:
>>>>>
>>>>> 1. DOS
>>>>> 2. FreeBSD
>>>>> 3. FreeBSD
>>>>>
>>>>> I can boot to FreeBSD (the new slice is fine) by choosing option 3
>> but
>>>> the
>>>>> windows/dos option is fried.
>>>> The MBR itself looks OK.   According to that piece of menu you
>>>> posted, you just added another bootable slice.  So, there are now
> two
>>>> bootable FreeBSD slices and one bootable Microsloth slice.   
> 
>>> Correct, I chose '1' and then the system hangs (no messages/errors).
> 
>>> I simply converted a 6GB FAT32 partition into a UFS2 slice (chopped
>>> into three 2GB partitions).
> 
>> Well, I still am guessing the problem lies in individual slices' boot 
>> sectors and not the MBR.  just try and set the bootable flags in the 
>> slices the way you think they should be and see what happens.   
> 
> In sysinstall I toggle bootable but it puts an 'A' which seems to mean
> auto-bootable. 
> I can only set one 'A' here.
> 
> --
> Peter
> 
> 

I tend to agree with Jerry and others that the problem is not with the 
MBR, but with the Windows boot sector in the first partition. If 
that's true, you can't fix it with sysintall or FreeBSD. You have fix 
it with Windows tools.

If you were running Windows 2000 or XP in the Windows partition, I 
would recommend that you use the Windows 2000 System Recovery Console 
and run the fixboot program to install a new Windows boot sector on 
the Windows partition. If you're running an older version of Windows, 
you need to find out what tool it uses to restore a boot sector.

Chances are in the process you'll wipe out the FreBSD MBR which you'll 
have to fix using FreeBSD. I guess that's where boot0cfg comes in, but 
I've never used it.

The best advice, though, is to backup everything you can before 
proceeding.

-- 
Ken Stevenson
Allen-Myland Inc.