master boot record

[kyeev]

Master boot record problems!!
I split my hardrive into 2 partitions using ranish partitiion manager (primary C: and extended D:). Everything worked fine until the registry file became damaged. This occured after the PC was moved a couple of hundred miles in a car (???). I decided to reformat my C drive and reinstall win98 whereupon I hit a problem that I can't solve.
Here's what happens...
1) Reformat of C: drive works fine.
2) attempt to transfer command.com to C: will not work because dos reports 'FAT tables are corrupted'
3) subsequent scandisk of C: drive reports Master boot record does not match C:. Scandisk then replaces copy 1 MBR with copy 2.
4) transfer of command.com to C: is now allowed
5) However PC hangs on reboot!!

Stuff I've tried:
1) removed all partitions using a) fdisk (fdisk/mbr switch will not start???)and b) ranish partition manager
2) replaced with single primary partition c: (have tried reformatting before and after reboot with no success)
3) rebooted pc with win98 boot disk
4) On restart partitions are back where they started ie. c: and d:

I'm guessing the two copies of FAT tables stored in mbr are rewriting each other or something. Basically I need a way of blanking EVERYTHING on my PC so the sodding thing will start. As far as I can see, neither fdisk or ranish partition manager nor scandisk seem to be able to rewrite the MBR correctly. And why won't fdisk/mbr start?
I'm sure the MBR isn't infected cos I've ran norton antivirus recovery disks and clean booted the PC.
(My PC is two years old and runs on dos 5.0 and win98)
And I'm going to kill it soon with an axe...

[YODA74]

don't know if i'm on the right track here but worth a try.

1) Install the disk in a booting windows 98 machine
2) rebuild partition table
3) rebuild extended boot sector (1st copy is enough)
4) set the first 4 bytes of the first FAT to 00000000

When Windows 98 detects that the first fat is corrupted, it automagically uses the second FAT.

Do you know what the default cluster size was.
you might have to use a file recovery software not sure about all this i'm sure some one here has a better grasp on this so hang out a while.

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Treading,Troden,Trails
HERE (http://www.davematthewsband.com)

[Rick]

If Ranish will allow you to do it.
Use it to remove all partitions .
It ( Ranish) is probably the reason Fdisk doesn’t work correctly.

Then run Fdisk to partition the drive again.
Using Fat16 ..
This will allow you to write over both copies of the MBR and force fdisk to do it.
Then do the same for the extended partition .
Format it if you like.

Then run fdisk again and remove all the partitions
run Fdisk again and redo it in Fat32.
** Remember to Reboot after each repartition **

I ran into something on the same lines after using linux on a drive and had to repartition it 3 times to get rid of all the old copies of the MBR
One more Note.
I have also seen the same thing happen to two other systems after being moved from one house to another in the front seat of a car. ( 10 miles )
The shock of each Bump in the road caused physical damage to the drive.
Crash the heads on the disks



[This message has been edited by Rick (edited 11-29-2001).]

[ranchdog]

Thanks Rick.


Learn something everyday.

http://www.PCGuide.com/ubb/smile.gif

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......Indecision may or may not be my problem......
...... Kickin' A Rock....

[ranchdog]

Thanks Rick.


Learn something everyday.

http://www.PCGuide.com/ubb/smile.gif

------------------
......Indecision may or may not be my problem......
...... Kickin' A Rock....

[kenja]

I'd download the "wipe" or "all zeroes" utility (sometimes within the diagnostic program) from the hard drive manufacturer, and put it on a bootable floppy.

[rond36]

I think kenja is on the right track use harddrive manufacturer utilities to write zero's to the whole drive wiping out the MBR, all partitions, and the FAT. After that fdisk and format and drive should be just like new

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Alright who messed it up this time!

[ranchdog]

True... A low level format will remove everything.

But I don't like to use it on a HDD if there is any other way. Especially a HDD that has some miles on it.

http://www.PCGuide.com/ubb/smile.gif

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......Indecision may or may not be my problem......
...... Kickin' A Rock....

[iisbob]

The zero utility they are referring to is not a true " low-level " format ranchdog, it simply writes 0's to all sectors of the drive; effectively "blanking " it-no different than data thats' being written to it in normal use.

Just in this case it's a bunch of " null " data. You can't really low-level format any drive larger than 500 mb's anyways without totally destroying the tables set up by the manufactorer.



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iisbob
""I was gratified to be able to answer promptly, and I did. I said I didn't know."
Mark Twain

[kyeev]

Update: Master boot record!!

OK, took the advice and downloaded wipe.com and zap.com which are supposed to wipe everything on the hardrive including the master boot record ie. they write zeros to the whole drive. However after running these utilities and rebooting the machine, the old partition information is still partially present. The primary partition is still present and the extended partition is present. The logical drive within the extended partition has been deleted though...
Whats going on??
Upon further mucking about, I find I can alter the extended partition to fat 16 or fat 32 but I CANT alter anything else.
Is my hardrive physically damaged?
Surely there should be no partition information remaining on the hardrive after a complete wipe unless there is a read/write problem? Other parts of the drive seem fine with regards writing information. scandisk of physical properties of hardrive finds no problems either.

Is it looking like I'll have to buy a new hardrive?? DOH!!

Thanks in advance
kyeev

[YODA74]

http://www.whitecanyon.com/siteindex_main.htm

you do not "low-level-format" IDE or ATA hard drives. This term is a misnomer from the old MFM hard drive days when a drive could have the tracks and sectors defined using a low level format.
The IDE or ATA drives we use today have all this information preset at the factory and a real low level format would destroy the drive or at least slow it down radically... you cannot redefine the tracks and sectors on these drives with a true low level format. Of course this is highly simplified for this discussion, but let us suffice to say that you cannot change the physical geometry of current IDE/ATA drives without destroying it... or what a low level format does is redefine the tracks and sectors on a hard drive. So... this is an old term that really does not apply to today's IDE/ATA hard drives.

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Treading,Troden,Trails
HERE (http://www.davematthewsband.com)

[This message has been edited by YODA74 (edited 12-04-2001).]

[kyeev]

nobody has any ideas?
I'm thinking the hardrive is physically broken at this stage.
What do you guys think?

[McWiggly]

Try this,

First you need a boot disk with debug.exe on it. A windows 98 boot disk should have it by default.

Here's the syntax

A:\debug

F 200 L 100 0

A CS:100

(Now you will see a set of hex numbers just keep typing)

####-#### MOV AX,301

####-#### MOV BX,200

####-#### MOV CX,1

####-#### MOV DX,80

####-#### INT 13

####-#### INT 20

####-#### G

Program terminated normally

Q

Now you can exit and run fdisk There will be NO partitions on your drive

[McWiggly]

Originally posted by kyeev:
nobody has any ideas?
I'm thinking the hardrive is physically broken at this stage.
What do you guys think?

Try this,

First you need a boot disk with debug.exe on it. A windows 98 boot disk should have it by default.

Here's the syntax

A:\debug

F 200 L 100 0

A CS:100

(Now you will see a set of hex numbers just keep typing)

####-#### MOV AX,301

####-#### MOV BX,200

####-#### MOV CX,1

####-#### MOV DX,80

####-#### INT 13

####-#### INT 20

####-#### G

Program terminated normally

Q

Now you can exit and run fdisk There will be NO partitions on your drive

[McWiggly]

sorry about the double

[McWiggly]

Sorry I missed a step on the last one
Ignore the other posts I sent

First you need a boot disk with debug.exe on it. A windows 98 boot disk should have it by default.

Here's the syntax

A:\debug

F 200 L 100 0

A CS:100

(Now you will see a set of hex numbers just keep typing)

####-#### MOV AX,301

####-#### MOV BX,200

####-#### MOV CX,1

####-#### MOV DX,80

####-#### INT 13

####-#### INT 20

####-#### (press your enter key)

G

Program terminated normally

Q

Now you can exit and run fdisk There will be NO partitions on your drive[/QUOTE]

[diurnal]

When you format try and type in format.format c: /s /u And see if that does it.

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Sledgehammer will save the day!

[kyeev]

OK, ran debug and entered the strings given.
Fdisked new partitions.
On restart, partitions still not rewritten.

This must mean the hardrive is not writing correctly to the mbr??
Does this mean the hardrive is physically damaged?

The only thing I can do is buy a new hardrive by the looks of things.
Or is there anything else I can try? I wonder if I've exhausted all possibilities at this stage.
Is the hardrive worthless or will I be able to partially use it if I buy a new hardrive.

Is it worth bringing the drive into a repair shop for someone to look at?

Any thoughts would be greatly appreciated
kyeev

[no-mbr]

Usually fdisk/mbr does just about anytihng you need it to. However, if you are not getting the partiton info to "stick", in other words the drive keeps coming back blank after you have "fdisked it" (say that 3 times in a row fast)then you are officially screwed. I have seen this happen on "well-used, well handled" drives. One of the circuits on the drive is no longer working correctly and will not "write" partinfo anymore to the drive.. when this happened to me WDC replaced my drive no charge...

[McWiggly]

Originally posted by kyeev:
OK, ran debug and entered the strings given.
Fdisked new partitions.
On restart, partitions still not rewritten.

This must mean the hardrive is not writing correctly to the mbr??
Does this mean the hardrive is physically damaged?

The only thing I can do is buy a new hardrive by the looks of things.
Or is there anything else I can try? I wonder if I've exhausted all possibilities at this stage.
Is the hardrive worthless or will I be able to partially use it if I buy a new hardrive.

Is it worth bringing the drive into a repair shop for someone to look at?

Any thoughts would be greatly appreciated
kyeev

You said Fdisked new (partitions) are you trying to build two partitions or are you wanting to build one primary using all available space? Try this, run debug again, then run Fdisk, when in fdisk select display partition information and see if there are any defined. don't create any partitions just yet, just display the partition info and post back

[McWiggly]

Remember to reboot after running debug

[kyeev]

OK, MBR update!
Tried a few things...

1) Booted with win98 boot disk.
Ran Debug. entered strings.
ran fdisk. no partitons listed. Good...
Rebooted computer again with win98 boot disk.
ran Fdisk... old partition information back.

2) Booted with win98 boot disk.
ran debug. entered strings.
ran fdisk. no partitions listed.
Rewrote mbr with fdisk to have one large partition.
Rebooted with win98 boot disk... old partition information back.

Also if I run debug and enter strings etc, then run fdisk, no partitions listed. but if I exit fdisk and then restart fdisk, the old partition information is back again.

Have tried using ranish partition manager instead of fdisk to partition but no good either.

AM I SCREWED????!!!!!

Thanks for your help guys.

[Paleo Pete]

OK...I'm not sure where all this has led, but a comment or two on low level formatting.

As iisbob said, low level formatting should not be done with IDE or SCSI drives, it is done at the factory and if you try it you cannot re-write the tables that tell the controller where the sectors and tracks are.

If you do try to low level format, most IDE drives will somply ignore the command, whether you use debug or not. If you do manage to do it, the drive will most likely then be useless. The PC Guide's Low Level Format (http://www.pcguide.com/ref/hdd/geom/format.htm) article has a better description than I can offer.

If you run fdisk and remove all partitions, reboot and the partitions are back again I would think the drive does have problems. That can happen after moving one in a vehicle.

When transporting, any bumps can cause the heads to "crash" against the platters and damage them, so the drive can no longer write. It's usually more common for one to start coming up with lots of bad sectors, which is actually due to the heads being unable to read and write properly. The heads are made of ceramic and fairly fragile. They can also scratch the surface of the platters, which are metal and coated with a thin layer of shiny magic magnetic stuff http://www.PCGuide.com/ubb/biggrin.gif

I've had to re-read this one several times, but from what I can see it looks like the heads may have been damaged and the drive could be gone.

I would try and use it as is on a test basis, run scandisk daily for a couple of weeks and see if it comes up with bad clusters. If it continuously finds more bad clusters it's a safe bet the drive is on its last legs.



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[kyeev]

NUTS!

[sea69]

had you tried DelPart (http://www.rustysmith.com/delpart.htmdelpart)

??


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[This message has been edited by sea69 (edited 12-11-2001).]