As you know, in the floppy format for xp and later os. There is an option to make the ms-dos boot disk, and it's ms-dos 8.0 (4.90.3000).

But where is the dos from? The answer is that the diskcopy.dll includes a 1.44 M floppy image. You can use a hex edit to grab the image from the dll. The ms-dos 8.0 from diskcopy.dll is a bit different from the winme dos.

But if you use a data recover software to search in the image you'll find that the ms-dos 8.0 image is actually a modified version of winme boot disk, you can find the deleted files.

In the picture is the floppy image from the diskcopy.dll in vista, and it was modified in 2005. The files with "X" are the files deleted from the original winme floppy, which is created in 2001.



There is one file named "?eadme.txt". It is actually a file described how the ms-dos 8.0 floppy in diskcopy.dll was made. Recovery it to readme.txt, you'll find the secret:
DOS Boot Disk Readme
======================
May 25, 2001
Aidan Low (aidanl@microsoft.com)

This directory contains the files that make up the DOS boot disk on whistler.

06/08/2000 05:00 PM 58,870 EGA2.CPI
06/08/2000 05:00 PM 58,753 EGA3.CPI
06/08/2000 05:00 PM 58,870 EGA.CPI
06/08/2000 05:00 PM 21,607 KEYB.COM
06/08/2000 05:00 PM 34,566 KEYBOARD.SYS
06/08/2000 05:00 PM 31,942 KEYBRD2.SYS
06/08/2000 05:00 PM 31,633 KEYBRD3.SYS
06/08/2000 05:00 PM 13,014 KEYBRD4.SYS
06/08/2000 05:00 PM 29,239 MODE.COM
06/08/2000 05:00 PM 93,040 COMMAND.COM
06/08/2000 05:00 PM 17,175 DISPLAY.SYS
04/07/2001 01:40 PM 9 MSDOS.SYS <-- should be system, readonly, hidden when copied to the floppy
05/15/2001 06:57 PM 116,736 IO.SYS <-- should be system, readonly, hidden when copied to the floppy

To prepare the disk image for the DOS boot disk, create a system disk on a Win9X Machine so that the boot sector is created properly.

Then copy these files over, setting the appropriate attributes. (the attributes are called out in the list above)

Finally, use the imgtool.exe tool to create a disk image from the floppy. Typically this will be something like

imgtool.exe \\.\a: c:\myimage.bin

======================
You can see that this is make by Aidan Low in 2001, in which the msdos.sys and io.sys is modified from the original winme boot disk. And the image is made with imgtool.exe, which can also be recovery from diskcopy.dll

very nice, didn't know that

OMG Thanks for this information!!!!

Another information about the diskcopy.dll is that there are only two versions ms-dos 8 images in diskcopy.dll. One is in xp sp2 and before, the other is in vista sp1 and later.

The first version was made in 2001, and the second one is made in 2005.

How we can extract this?

You can open the diskcopy.dll with any type of hex editor (e.g winhex).

Search for EB3C90, it is the head of the fat boot sector. Then extract the length 1,474,560 bytes from "EB". And you'll get a 1.44MB floppy image.

Ok and how to search to EB3C90...
I dont know how WinHex work XD

Would anyone be willing to PM me a copy of the .IMG file?

To your knowledge, is there any checking done on the content of the image embedded in diskcopy.dll, or could it theoretically be swapped with any image?

I think it is possible to replace the image with another 1.44M floppy image.

can somebody upload a image to share.longhorn.dk ?

Hate to spoil the moment here but anyone involved with tihiy's fixes for win98se knew of it, and knew
that it could be extracted with any resource editor like reshack or the likes.
And it really is just a millennium edition bootdisk, not something that reports as dos 8 or the likes.

http://share.longhorn.dk/get.php?id=123

This one is from 7 x64 Ultimate, your welcome

awesome, thank you

Would it work on x86 also ?

The image from x86/x64 are same. And all image are english version no matter what language the diskcopy.dll is.

ahh great...

I'm thinking to soon add a file browser to share.longhorn.dk since its hosting alot of good stuff

The diskette has been dismantled at the starman's site.

It's pretty much the Windows ME install diskette, with new files added to it.

Not really-really a secret, or at lest an already revealed one.

Here (includes tool(s)) to extract the image:
http://www.911cd.net/forums//index.php?showtopic=16745

jaclaz

This is the earlier version of diskcopy.dll (xp sp2 and earlier), which is made in 2001.

Here I show the newer version, which includes the readme describing how the floppy image was made by Microsoft workers .

As a fan of MS-DOS, this is really an amazing find.

As I posted above, it was a known fact amongst those who develop tweaks and fixes for early OSs, and could be extracted using any resource editor.