View Full Version : 'Invalid media or Track 0 bad - disk unusable' error message

19-04-2002, 12:24 AM
In attempting to connect a slave hard drive to an old computer I encountered difficulties which have resulted in now not being able to access my existing C drive. Scandisk attempts to run but fails and in attempting to reformat my main C drive I get the above error message! This then prevents me from reloading windows. I am suspicious that my attempted slave drive may have a virus or Have I simply mucked up some where?

Many thanks.

19-04-2002, 03:20 AM
Go into your BIOS and try configuring your hard drive.

Then maybe a clean of the memory boot sector running fdisk /mbr at a dos prompt booting from a startup disk and try restarting and running Windows.

19-04-2002, 02:41 PM
That message is usually Bad News. When a floppy gets that, it gets tossed.

FDISK /MBR won't work. It will decide that the track is bad too.

There is an IBM free programme called zap.exe which is alleged (by IBM) to erase that track on a hard disk. I would bet that it works. It would be worth a try. I've given the URL here (search for zap.exe) but I don't know if the posters had any success. You will find it with google too.

Like everything else, read the instructions --- there's a bit of reading on the download page.

But I don't like your chances. There is track substitution for faulty tracks, but not that one. It's the one part of any disk which HAS to be good.

19-04-2002, 04:48 PM
Zap.exe overwrites, with zeros, the first 128 sectors of a hard drive.

All data is lost including the master boot record, the partition table information and the FAT for the first primary partition as well as any data in the first two sectors of the first primary partition.

The action (of using Zap.exe) is irreversable and all data overwritten in the first 128 sector completely irrecoverable.

The action of removing the partition table information (stored in the last 64 bytes of the first sector) and the FAT of the primary partition means that access to other data on the hard drive is lost.

The only method of recovering other data on the hard drive is to use a specialised data recovery programme in DOS.

Zap.exe and it's partner Wipe.exe (which overwrites an entire hard drive with zeros) are both available in the download section of IBM's site.

20-04-2002, 04:26 PM
Just had another look --- is the 'slave' drive still connected?

If so, it's probably set up so that it is trying to be master at the same time your C: master is trying to be master. That will certainly cause problems ...

Even if you have removed it, it could easily have caused the problem in your C: drive.

Any writes to the disks could have given unreadable sectors. It only needed one write to that track to cause that error message. DOS does not do error checking on writes.

Note Merlin's warning about the effects of zap.exe. But once that track is unreadable, the disk is unusable without fixing that track and making it readable again.

FDISK /MBR will not restore the partition info and FAT information.

23-04-2002, 02:39 PM
I once had a similar problem when trying to slave a small drive to an existing drive - somehow the MBR of the existing one got overwritten with the MBR of the slave and I couldn't boot from existing. I eventually fixed the problem by booting from a floppy and using Disk Editor from a DOS version of Norton Utilities to rewrite the partition table (which is found in the MBR, near the end). I used NU from a floppy which contained a cut-down version made by deleting things irrelevant to the job in hand like batch enhancer, line print, file fix etc until the remainder fitted on a floppy. To rewrite the partition table you need to do a complex encoding of the
start and end sector definitions. I worked out how to do that from info from 2 books - Que's 'Guide to data recovery' and 'PC Data Recovery and Disaster Prevention' (Harris, S. and S. Nugus). One sector of my FAT 1 was also corrupted but i corrected that by pasting a copy of that sector from FAT 2. With those corrections the full function of the existing drive was restored.

In your case, however, if you are happy to risk losing the contents of your existing C drive and rebuild it from scratch, it might be worth disconnecting your slave completely, redoing your HD setup in BIOS and trying fdisk/mbr from a bootup floppy from the same OS as is installed on your C. With a bit of luck this will correct your partition table and MBR generally and restore your C drive. If you then want to retry connecting your slave I suggest that you firstly make a spare copy of your mbr (using Disk Doctor) at Cylinder 0, Head 0, Sector say 10 or 20 (wherever you find an empty sector). If the MBR corruption recurs you can then simply restore it from the copy. I think making such a spare MBR copy is worthwhile on any computer in case of subsequent corruption.