MBR & Directory recovery..

My old XP system's MB died, taking the MBR off it's HD.

Why do I 'know' it was the MB? First, horiz synch started with jitters (onboard video). I put in a new video card & reset the BIOS to use the PCI-E slot.. Then the PC would 'hang' after BIOS attempted to boot XP, 2-4 power on/offs would let it continue.. Then would get occasional MBR read error, power on/offs would eventually get it going.. All ran fine once it was running. (& backed up important data). Then about two weeks from start of problem, got where BIOS would not start, just DOA, black screen of death.. Nada..

I tried booting that HD on another PC but it claimed it was missing the MBR.
BIOS check on that PC reported the correct 1st partition size about 238gb of the 250gb HD, indicating to me that it read the partition record (2 partitions, ~238gb C: + ~12gb recovery D

Advice was given to me to INITIALIZE the drive & it'll be usable again.
BUT - will that allow me to get the directory and find all my data? (assume it was *ONLY* the MBR that didn't get rewritten when the MB died)..
Somewhere in the dim past I recall reading/hearing the Windows directory, since NT or 2000, can be anywhere on the HD? and the pointer's are in the MBR?? If that's right, then how do I find the data or directory??

Is there freeware/shareware or do I have to roll the dice and buy some product? (recommendations?). Or cheaper to let a shop do it?

I'm new on this board, but was an Ex PCDOS expert, use to know how to write in assembler to read & repair boot sectors, but long retired and currently just OK with my Windows knowledge, so go ahead and throw the tech terms and good-places URLs.

Thanks much
Bob K.

 

Hi Bobk and welcome to WindowsBBS

If you need the data do not initialize (format) the drive

Since you've backed up important data I'd be tempted to run diagnostics on the drive, use the appropriate tool from the links below...

Disk Diagnostic Software ....

ExcelStore

Hitachi/IBM

Samsung

Seagate, Maxtor, Quantum

Western Digital

Fujitsu

If you're lucky and it is only the Master Boot Record affected (though I doubt it) post back with your current OS and someone may be able to assist with repairing it.

Whilst your here why not take the time to enter your system details...

If this is your main system it would be helpfull if you add your system details to your profile. Please click on the link and follow those instructions it could save some time when resolving this or further issues.

A common error is to forget to show your system details in your profile

If you do add your system specifications be sure to do the above

 

You can try 'testdisk' , it can rewrite the MBR and VBR's. Be sure to read the how to use first.
http://www.cgsecurity.org/index.html?testdisk.html

On the XP cd in a I386 sub folder is a program named 'diskprobe' (not sure of the sub folder name) that can be used to read/write directly to any sector of hdd . Use only if you know what you are doing to manually rewrite the mbr .

 

Thanks for that heads up.. I'll look into it.

I alos found the NTFS.COM web site that fully describes the file structure including the MBR.
It showed me that the advice I was getting from several was misleading if not just flat wrong.

The only time you'll see the "missing MBR" error msg is when the last two bytes (or more) are not in the MBR sector. If you get that, AND, the correct partition size when you use the BIOS diagnostics (as I did), then the partition table is intact.
IF those last two bytes are there, but the code is bad, you'll see BIOS do it's thing, then a HANG.. as BIOS gave control to that bad code.

Knowing these things, and finding a bootable CD IMAGE loaded with diagnostic tools it what's needed when the PC goes bad.

Bob

 

For a VERY COMPLETE description of MBR's etc .. see:
http://thestarman.narod.ru/asm/mbr/index.html#MBR

Also for another discussion..
http://www.sysint.no/nedlasting/mbrfix.htm

What I've found most fustrating, is every OLD utility program I've
tried, has Windows 7 64bit REFUSING to run the programs - for being
'incompatible with the (new) version of Windows'!!

Good luck to you all,
Bob K.

 

Have never used '7' but XP will not allow most old programs to directly access the hdd, they must be written for XP to do so. On the XP cd , could also be on 7, is a added but not installedd program called 'diskprob' that will read/write to hdd.

 

I've had a few ideas from here, but no solution yet. Here's where I'm stuck.
1 Every 'neat' disk read/write/edit program WILL NOT run on Window 7. There is no DISKPROBE for W 7, the one from XP & Vista won't run on 7. I only have a WORKING Windows 7 computer.
2 I have a GOOD Windows XP HD, at least the bios of the new PC says so, I just get "Not an MBR" error. Indicating invalid 'signature' no x'55AA' - per that MBR explanation URL I posted above.
3 When it was swapped in as the only HD on the new PC, it showed the correct bootable partition size (of 2) meaning - that the x'55AA' is missing and no boot code was attempted to be run.

I just need to: Put the x'55AA' back as the signture.
Is there any program that will run on Windows 7 that can do this?
Is there a CD image with a bootable system (.ISO image) containing such tools?

 

Have you ran diagnostics on the drive yet?

Most of the tools in my previous post have bootable images to burn to floppy or CD.

 

Other than the diagnostics I've mentioned in my previous posts?

I've had problems with those other images too. But I'm going to try using Nero..
Win 7 CD burn doesn't seem to work the way I expected it to.

 

You could boot up with a live linux cd and use linux tools to rewrite the MBR signature. Just remember if you manually enter the signature code '55AA' it must be written as 'AA55' into the last 2 sectors of MBR. All bytes must be written in little endian format.