The other day I found an old floppy from the 80's. I inserted it in my USB floppy drive and I got a message from Microsoft security essentials that the disk was infected by a boot virus.

I supposed that a modern AV couldn't fix such an old virus, so, before pressing "fix the problem" I made a disk image with RawwriteWin.

MSE "fixed" the virus with a full drive format. Shoot.

I told myself: "who cares, I have the full image"

Then I noticed my disk was a 720k disk, and rawwritewin only makes 1.44 images (I have a 1.44 mb image)

Rewriting the image on the disk fails.

Reading the image with dosbox fails.

Reading the image with virtualbox fails.

With an hex editor I can see that my middle school data is still in the image, why I can't mount it? It's because it's too big? If I reduce the size to 720k trimming the file, will it work?

Edit: just did split -b 737280 myimage.img out but dosbox still can't open this image... (can open, but shows empty and with 2 tb free size)

  • You could try running a DOS VM with its floppy disc mapped to the image file.
    – AFH
    Jul 4, 2014 at 23:54
  • No, tried in virtualbox+freedos, the virtual image is unreadable Jul 4, 2014 at 23:56
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    All I can now suggest is: 1. Maybe the formatting only deleted the partition or directory structure: if so a partition or file recovery program might find and extract files from the floppy. 2. Have a look at the created image with a hex lister to see if there are periodic blocks of zeroes, indicating that each read was half the expected length, but the full length was written: if so a 10-line C program could make a corrected image which would be mountable in the DOS box. 3. Try a repair CD: if a Windows disc like UBCD4Win doesn't help, try a Linux-based disc or even a try/install Live CD.
    – AFH
    Jul 5, 2014 at 0:34
  • the image looks fine in an hex editor... imgur.com/nh6ZvVP Jul 5, 2014 at 0:50
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    If the image is correct for the first 720KB, then the Linux dd program will do a raw write for you and you should get your floppy back (but try it on a blank floppy, in case you want to try to recover files from the formatted one). You can copy the 1.44MB file and leave dd to error when it has filled the floppy: it will still have written everything.
    – AFH
    Jul 5, 2014 at 1:19

1 Answer 1


try either WinImage or a linux distro maybe a live CD/DVD or virtual machine.

  • i'll try to download winimage Jul 5, 2014 at 0:00

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