recover deleted files on old DOS system

March 12, 2008 9:32 AM

Help me recover some deleted files on an old DOS system.

I have tried:

the undelete command: it found the files in question, but said the first block or sector or something was corrupt or unreadable or something. Subsequently running undelete turns up nothing now. (it's the plain-jane undelete)

Attach as second drive to XP to run Easyrecovery: Unknown partition, even though it's fat16. I now know XP can't read fat16 for some stupid reason.

Use UltimateBootCD: I tried 2 or 3 of the recovery programs there, but they said the partition was corrupt or unreadable.. something along those lines.

It still works perfectly fine as a dos machine. The files in question are less than 10 small text files. It's an old 40mb drive. Hope this helps...

posted by imaswinger to computers & internet (9 comments total)

XP definitely supports FAT16. I don't think that's the problem.
posted by zsazsa at 10:00 AM on March 12

I ran across a number of mentions of it not working, so I just assumed that was it. I know it's _supposed_ to, but I read that it didn't. When I stuck it in my XP machine, a small partition showed up with a few random files, no way to access the dos stuff.
posted by imaswinger at 10:09 AM on March 12

Sounds like the filesystem is hosed on there. Not sure what you can do at this point. Most undeleters assume the filesystem is in one piece and that the file is only marked as deleted. If the disk is corrupt on the filesystem or below level then that would explain why you cant mount it anywhere.

Maybe grab a linux live disk (knoppix) to verify.
posted by damn dirty ape at 10:27 AM on March 12

Have you tried a DOS bot disk? DOS 6.22 can be found here. Also some Win95/98/XP disks.

A drive utility might help in a pinch, if the file table is corrupt; running CHKDSK might help.
posted by caution live frogs at 10:32 AM on March 12

I tried it in a win98 machine and got the same result as in XP. it's 540mb, 77mb used (must have confused it with something - or one of the file recovery programs showed 40mb or something), and the files that show up are:
command.com
dblspace.000
dblspace.bin
dblspace.ini
file0001.chk 2, 3
io.sys
msdos.sys

the file0001.chk has a reference to c:\windows\temp in it, so I'm guessing this is an old win95/8 partition and the dos partition is not showing? But it boots right into dos if you make it the master.

What I use the dos boot disk for?

I'm scared to run chdsk or anything that writes to the disk until I figure out what's going on, or at least until I can make an image of the disk (which I'll do right now).
posted by imaswinger at 10:44 AM on March 12

You probably have a compressed disk (indicated by the presence of the dblspace.* files).

To tell if the disk is compressed, type DBLSPACE /LIST at the DOS prompt. It'll list the drive if it's compressed.

If it is compressed, this would explain why Windows XP craps out when reading the partition. I know there is no native way to read DBLSPACE or DRVSPACE compressed disks in XP. That doesn't rule out the possibility that this tool exists. A cursory Google check didn't turn up much, but who knows.

You could read the drive in XP by uncompressing it, but this will rewrite all the sectors and make undelete impossible. So yeah, not an option.

The only other thing I can think of is trying to get your hands on a old copy of Norton tools for DOS or something similar.
posted by dosterm at 11:34 AM on March 12

XP definitely supports FAT16. I don't think that's the problem.

Seconded. That's not the issue.
posted by SlyBevel at 11:38 AM on March 12

another note.. I try to boot from it on my machine - non-system disk. I put it back in the old box and it boots up just fine.

Thanx for the compressed tip.. I'll see what I can do from here...
posted by imaswinger at 11:48 AM on March 12

I tried dblspace /list and is in fact a compressed C drive, with D - G available for dblspace, and then J as the rest of the disk.

Putting the drive in it's own computer, and using a dos boot disk, I get the files listed above (command.com, etc.), not the compressed drive.

Putting the disk in my computer, trying to use any sort of boot disk (hirens 9.4) it hangs. Unplug the hard-drive, and it starts right away. Disk-Image floppy boot, also hangs if this possessed hard-drive is connected.

the computer the hard drive is from, has only one IDE slot (on a daughter-board of some kind), and a soundcard with a few IDEs to which the non-functional CD-ROM is attached. Perhaps if I got that cd-rom working I could use the hirens bootdisk to recover the few text files? But I still want to be able to back up the whole drive...

I can't help but think I'm missing something here... it should not be this difficult to back up a disk! (then I'll worry about the recovery...)
thanx again for all the help.
posted by imaswinger at 12:54 PM on March 12