Identifying the cause of data corruption
There are some specific steps which if followed in a sequence, may help us to find the area of corruption. These steps have been described with recovery procedure as follows:
Boot the system with bootable floppy
Boot your system with a bootable floppy or CD of the operating system you were using. Try to read the logical drives C: or D: or whatever. If the drive(s) is accessible, just copy all the data off the drive. Now you can figure out why the disk is not booting properly, with less stress.
Verify the MBR Information
The first and most important piece of data on the hard disk is the MBR and the table that it carries within it, the partition table. The small disk Editing tool named “TTEDITOR.EXE” has been given in the disk included with this book. Or you can use any other program to analyze the hard disk.
Diskedit will be the most suitable program to analyze the disk for data recovery purpose. Well, whichever program you feel easy to use is upon you. Try to read MBR and especially its partition table.
As you have seen in the description of MBR, discussed in this chapter, In the second half portion of MBR, there is some readable text which displayed as error message by this, if there is something wrong with it. These text messages are displayed something like:
“Invalid partition table, Setup can not continue”
“Error loading operating system, Setup can not continue”
If these error messages are not available this indicates the corruption of MBR. There may also some illegal message instead of this like, “Your system has been hacked by…..” or any other unexpected message. It indicates that there is something seriously wrong with the MBR, and most probably, it is due to some VIRAL infection
Now check the partition table of MBR after the initial 446 bytes. If the partition table is blank, you will not see any error message at boot time. DOS ignores a non partitioned drive. If there is not any bootable floppy in drive A:, the system will request for a bootable floppy to be inserted in drive A:.
The important thing to be noticed here is that the partition table should not be blank on a drive that was previously working, so something has erased it. If the partition table is blank, restore the MBR from the backup.
If the backup does not work, even after the successful completion of restoring process, there is physical damage on this sector. Try the programming techniques of data recovery, given in the next chapters to recover the data. If you are not a programmer at all, better to go to any good data recovery center.
If you not have any backup of MBR try to write partition table manually with some disk editing tool, like Diskedit, how ever it is very difficult to do so in some cases.
For those users who are not the programmers and also do not have any backup, may use the method which I have been using since my data recovery project development time, in my college days.
What you have to do is, just search the computer near you, which has almost same size of disk, with same number of partitions and the most important thing the same operating system which was in your computer.
However it works completely, most of the time. But if not so, at least it may help you to access the first partition of your disk. Even your operating system will also boot normally, if it was installed in the first partition and if the other information are not corrupted.
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