Re: OT File recovery Software

Oh contrar, I have used it many times over the years, but never bothered to
understand it the way you have.

Ed
"Sunshine&Lollipops" <NotARealEmailAddy@xxxxxxx> wrote in message
news:TsMTe.1348$mj1.561@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> I guess some of you never used the fix MBR command?
>
> MBR is damaged
> The Master Boot Record (MBR) will be created when you create the first
> partition on the hard disk. It is very important data structure on the
disk.
> The Master Boot Record contains the Partition Table for the disk and a
small
> amount of executable code for the boot start. The location is always the
> first sector on the disk.
>
> The first 446 (0x1BE) bytes are MBR itself, the next 64 bytes are the
> Partition Table, the last two bytes in the sector are a signature word for
> the sector and are always 0x55AA.
>
> For our disk layout we have MBR:
>
> Physical Sector: Cyl 0, Side 0, Sector 1
> 000000000 33 C0 8E D0 BC 00 7C FB 50 07 50 1F FC BE 1B 7C
> 3AZ??.|uP.P.u?.|
> 000000010 BF 1B 06 50 57 B9 E5 01 F3 A4 CB BE BE 07 B1 04
> ?..PW?a.o¤E??.±.
> 000000020 38 2C 7C 09 75 15 83 C6 10 E2 F5 CD 18 8B 14 8B
> 8,|.u.??.aoI.<.<
> 000000030 EE 83 C6 10 49 74 16 38 2C 74 F6 BE 10 07 4E AC
> i??.It.8,to?..N¬
> 000000040 3C 00 74 FA BB 07 00 B4 0E CD 10 EB F2 89 46 25
> <.tu»..?.I.eo?F%
> 000000050 96 8A 46 04 B4 06 3C 0E 74 11 B4 0B 3C 0C 74
> -SF.?.<.t.?.<.t.
> 000000060 3A C4 75 2B 40 C6 46 25 06 75 24 BB AA 55 50 B4
> :Au+@?F%.u$»?UP?
> 000000070 41 CD 13 58 72 16 81 FB 55 AA 75 10 F6 C1 01 74
> AI.Xr.?uU?u.oA.t
> 000000080 0B 8A E0 88 56 24 C7 06 A1 06 EB 1E 88 66 04 BF
> .Sa?V$C.?.e.?f.?
> 000000090 0A 00 B8 01 02 8B DC 33 C9 83 FF 05 7F 03 8B 4E
> ..?..<U3E?y..<N
> 0000000A0 25 03 4E 02 CD 13 72 29 BE 46 07 81 3E FE 7D 55
> %.N.I.r)?F.?>?}U
> 0000000B0 AA 74 5A 83 EF 05 7F DA 85 F6 75 83 BE 27 07 EB
> ?tZ?i.U.ou??'.e
> 0000000C0 8A 98 91 52 99 03 46 08 13 56 0A E8 12 00 5A EB
S?'RT.F..V.e..Ze
> 0000000D0 D5 4F 74 E4 33 C0 CD 13 EB B8 00 00 00 00 00 00
> OOta3AI.e?......
> 0000000E0 56 33 F6 56 56 52 50 06 53 51 BE 10 00 56 8B F4
> V3oVVRP.SQ?..V<o
> 0000000F0 50 52 B8 00 42 8A 56 24 CD 13 5A 58 8D 64 10 72
> PR?.BSV$I.ZX?d.r
> 000000100 0A 40 75 01 42 80 C7 02 E2 F7 F8 5E C3 EB 74 49
> .@xxx?C.a?o^AetI
> 000000110 6E 76 61 6C 69 64 20 70 61 72 74 69 74 69 6F 6E nvalid
> partition
> 000000120 20 74 61 62 6C 65 00 45 72 72 6F 72 20 6C 6F 61
table.Error
> loa
> 000000130 64 69 6E 67 20 6F 70 65 72 61 74 69 6E 67 20 73 ding
> operating s
> 000000140 79 73 74 65 6D 00 4D 69 73 73 69 6E 67 20 6F 70
ystem.Missing
> op
> 000000150 65 72 61 74 69 6E 67 20 73 79 73 74 65 6D 00 00 erating
> system..
> 000000160 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................
> 000000170 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................
> 000000180 00 00 00 8B FC 1E 57 8B F5 CB 00 00 00 00 00 00
> ...<u.W<oE......
> 000000190 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................
> 0000001A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................
> 0000001B0 00 00 00 00 00 00 00 00 A6 34 1F BA 00 00 80 01
> ........¦4.?..?.
> 0000001C0 01 00 07 FE 7F 3E 3F 00 00 00 40 32 4E 00 00 00
> ...?>?...@xxxxx
> 0000001D0 41 3F 06 FE 7F 64 7F 32 4E 00 A6 50 09 00 00 00
> A?.?d2N.¦P....
> 0000001E0 41 65 0F FE BF 4A 25 83 57 00 66 61 38 00 00 00
> Ae.??J%?W.fa8...
> 0000001F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 AA
> ..............U?
>
>
> What will happen if the first sector has been damaged (by virus, for
> example)?
>
> Lets overwrite the first 16 bytes with zeros.
>
> 000000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................
> 000000010 BF 1B 06 50 57 B9 E5 01 F3 A4 CB BE BE 07 B1 04
> ?..PW?a.o¤E??.±.
>
> When we try to boot after hardware testing procedures, we see just blank
> screen without any messages. It means the piece of code at the beginning
of
> the MBR could not be executed properly. That's why even error messages
could
> not be displayed. However, if we boot from the floppy, we can see FAT
> partition, files on it and we are able to perform standard operations like
> file copy, program execution... It happens because in our example only
part
> of the MBR has been damaged which does not allow the system to boot
> properly. However, the partition table is safe and we can access our
drives
> when we boot from the operating system installed on the other drive.
>
> What will happen if sector signature (last word 0x55AA) has been removed
or
> damaged?
>
> Lets write zeros to the location of sector signature.
>
> Physical Sector: Cyl 0, Side 0, Sector 1
> 0000001E0 41 65 0F FE BF 4A 25 83 57 00 66 61 38 00 00 00
> Ae.??J%?W.fa8...
> 0000001F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ................When we try to boot now, we see an error message like
> "Operating System not found".
>
> Thus the first thing if computer does not boot is to run Disk Viewer and
> check the first physical sector on HDD, whether it looks like valid MBR or
> not:
>
> a.. check, may be it's filled up with zeros or any other single
character
> b.. check whether error messages (like you can see above "Invalid
> partition table"...) are present or not
> c.. check whether disk signature (0x55AA) is present or not
> The simplest way to repair or re-create MBR is to run Microsoft's standard
> utility called FDISK with a parameter /MBR, like
>
> A:\> FDISK.EXE /MBR
> FDISK is a standard utility included in MS-DOS, Windows 95, 98, ME.
>
> If you have Windows NT / 2000 / XP, you can boot from startup floppy disks
> or CD-ROM, choose repair option during setup, and run Recovery Console.
When
> you are logged on, you can run FIXMBR command to fix MBR.
>
> Also you can use third party MBR recovery software or if you've created
MBR
> backup, restore it from there (Active@ Partition Recovery has such
> capabilities).
>
> What will happen if the first sector is bad/unreadable?
>
> Most likely we'll get the same black screen, which we got when trying to
> boot. When you try to read it using Disk Viewer/Editor you should get an
> error message saying that sector is unreadable. In this case recovery
> software is unable to help you to bring HDD back to the working condition,
> i.e. physical partition recovery is not possible. The only thing that can
be
> done is to scan and search for partitions (i.e. perform virtual partition
> recovery), and in case if something is found - display them and give the
> user an opportunity to save important data to another location. Third
party
> software, like Active@ UNERASER, will help you here.
>
> NTFS Recovery Concepts | Next
>
>
>
> "Alex" <abarna@xxxxxxxxx> wrote in message
> news:AJHTe.27258$mb4.19321@xxxxxxxxxxxxxxxxxxxxx
> > MikesBrain wrote:
> >
> > <snipper>
> >> You can get a full Linux OS designed to be run direct from
> >> the CDROM. Its got loads of tools you could probably have
> >> used to mount the suspect drive and recover the files from.
> >>
> >> Search "Knoppix".
> >
> > That's great if you read German. Even the U of Wisconsin archive is
> > mostly in German. I did finally find an EN version at the bottom of
> > the page.
> >
> > http://mirror.cs.wisc.edu/pub/mirrors/linux/knoppix/
> >
> >> I think there is a FreeBSD version too.
> >>
> >> They're free to download and use. No registration required. ;)
> >
> > I could have used this last month when my Hard drive lost it's boot
> > sector thanks to conflicts with the onboard drive controller & a
> > window$ update. When I got the computer working I found a Sony update
> > to fix the problems caused by the window$ update.
> >
> > The major problem with M$ products is the fact there is a large
> > profitable industry based on causing & correcting problems for M$
> > product users.
> >
> > GramPaHugs,
> > Alex,
>
>


.

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