Bad MBR

[jw]

I suddenly am getting hard drive error that the system says is due to
a bad MBR. How can I fix that?

 

[Bryce]

I suddenly am getting hard drive error that the system
says is due to
a bad MBR. How can I fix that?

You could buy a used MBR on EBay and install that. If you
share a little more about the problem, somebody might have a
better idea. What operating system? I'm gonna guess that
this happened during boot. Does the computer still boot
sometimes? Do you have a recent backup?

 

[jw]

first thing I'd do is backup the data

No data to worry about,

pop the drive in another machine and copy over anything you need.


next would be to run the manufacturer's harddrive diagnostic

don't have one.

If it says the drive is bad...
then you will need to replace the drive


now, if the drive turns out ot be ok

you will simply need to repair the mbr


if you are using XP

I am. Sorry I didn't say.

use your XP cd to boot to the repair console

then issue the command fixmbr

Hangs up at 'starting windows'

but you did not state your OS so who knows?

Again - sorry.

 

[jw]

You could buy a used MBR on EBay and install that. If you
share a little more about the problem, somebody might have a
better idea. What operating system? I'm gonna guess that
this happened during boot. Does the computer still boot
sometimes? Do you have a recent backup?

XP.

I pulled it from a broken machine, which would not boot.
I mounted it as a second drive in my XP machine to look at it.
It had two partitions in 80GB.
I re-formatted both using xp's 'format'.
I re-mounted it as c drive in my XP machine (removed original).
When I tried to install XP on it, it gave me the bad mbr message.
So here I sit, stimied.

Thanks
Duke

 

[Bryce]

XP.

I pulled it from a broken machine, which would not boot.
I mounted it as a second drive in my XP machine to look at
it. It had two partitions in 80GB.
I re-formatted both using xp's 'format'.
I re-mounted it as c drive in my XP machine (removed
original). When I tried to install XP on it, it gave me
the bad mbr message. So here I sit, stimied.

Thanks
Duke

Format just fiddles with the existing partitions, which are
described in the partition table that's part of the dreaded
MBR. The boot record is not altered by format.

Since there's nothing to save on the disk, why don't you use
the manufacturer's utility to write nulls to the whole disk.
That will zero out the entire mbr and leave a like-new disk
for your windows install.

Bryce

 

[jw]

Since you formatted both partitions, why not delete both partitions and
create just one (or recreate the two of them at whatever sizes you want)?
The setup program for Windows XP should let you delete and [re]create
partitions, and then format them. The install of Windows XP will step on
the bootstrap area of the MBR. The only parts left are the partition tables
and the disk signature.

You are a mind reader. I did just that using PQ Magic. Seemed to
work. I formatted the large partition, but now the installation hangs
up halfway through the beginning loads.

Duke

 

[David W. Hodgins]

work. I formatted the large partition, but now the installation hangs
up halfway through the beginning loads.

Does the bios for that system have an option for "virus protection"?
If it does, and it is enabled, that would prevent writing to the
first sector, where the mbr is stored. Try disabling it.

Regards, Dave Hodgins

 

[VanguardLH]

Since you formatted both partitions, why not delete both partitions and
create just one (or recreate the two of them at whatever sizes you want)?
The setup program for Windows XP should let you delete and [re]create
partitions, and then format them. The install of Windows XP will step on
the bootstrap area of the MBR. The only parts left are the partition tables
and the disk signature.

You are a mind reader. I did just that using PQ Magic. Seemed to
work. I formatted the large partition, but now the installation hangs
up halfway through the beginning loads.

Duke

Bad install CD. Bad hard disk.

The format didn't hang but the install did. So create a c:\tmpinst folder
and see if you can copy all the files from the install CD into that temp
folder on the hard disk. If so, run the install from there. If that works,
you have a flaky install CD (or a CD drive that might need replacing). You
could get the hard disk manufacturer's diagnostic utility and run it against
the hard disk to see if it found a problem with that device.

 

[dennis]

Does the bios for that system have an option for "virus protection"?
If it does, and it is enabled, that would prevent writing to the
first sector, where the mbr is stored. Try disabling it.

Modern OSes talk to the harddrive directly, so such a setting wouldn't
matter very much.

 

[Bryce]

I think most readers will know what you meant to say. I'm
sure you mean to say "You could buy a used disk on eBay
and install that...". Since the MBR is on the disk, it
isn't something you could buy separately.

<snip>

Don't go putting words in my keyboard. I have a drawer full
of used MBR's. Open the drive enclosure, clamp the disk in
a suitable vise, remove the two tiny screws that secure the
MBR to the first track ... voila! (Works best on April 1.)

In a more serious tone, I would not urge anybody to buy a
used drive. New drives with huge capacity are very
affordable, and probably more trustworthy.