China DOS Union

I have read your article about dual-booting between DOS and Win2000/NT/winxp before, and I have successfully set up dual-boot between winxp and DOS. But I found that the prerequisite is that there is a bootsect.dos file in the root directory of the C: drive. If this file does not exist, the dual-boot cannot be successfully set up. The小弟I am installing now has no bootsect.dos file in the root directory of win2000. Now the problem is how to manually create the bootsect.dos file. Please guide the webmaster, thank you.

（注：原文中“小弟”是比较口语化的自称，英文中可以用 "the user" 等简洁表述，这里按照要求直译了。）

Yes, as I mentioned in that article, the key is to have the BOOTSECT.DOS file in C:\. I made a major revision to that article some time ago. I wonder if you've seen the new version. Here's an excerpt from the original text:

The boot of DOS requires the boot sector and boot files of the DOS system. The key to installing DOS after installing WinNT/2K/XP is to establish them. Everyone may ask, after the system installs WinNT/2K/XP, isn't the content in the master boot sector replaced with non-DOS? Why can it still boot to DOS through the startup menu mentioned above? This is because if DOS (including MS-DOS 7.x built into Win9x) was once installed on the system, WinNT/2K/XP will automatically create the BOOTSECT.DOS file in the primary boot partition (usually drive C) during installation, and this file retains the boot information of DOS. When you select to boot DOS in the startup menu, WinNT/2K/XP uses this file to enable DOS to boot. Therefore, if the BOOTSECT.DOS file already exists in C:\ (that is, the primary boot partition), you don't need to manually create this file. You can directly copy the IO.SYS, MSDOS.SYS, and COMMAND.COM files of DOS (such as MS-DOS 7.10) to C:\ (it's best not to use the SYS command to transfer the system, for details, see the introduction in the next paragraph), and then modify the BOOT.INI file as described below.

For the DOS system boot files, you know you can use the SYS command自带 by DOS to transfer. However, if you do it directly, only DOS can boot, and the boot information of WinNT/2K/XP will be overwritten, resulting in inability to boot. To enable both DOS and WinNT/2K/XP to boot, there are several methods. You can use a very practical tool called BOOTPART, which can be found in the "System Tools" on this site. Its functions are powerful, such as writing the boot information of the specified system into the boot sector, including DOS6, DOS7 (Win9x), WinNT (/2K/XP). For example, to write the boot information of MS-DOS 7.10 (Win98) to drive C, you can use the command BOOTPART WIN98 BOOT:C:. Therefore, the specific method is to first use the SYS command (such as SYS C to transfer the DOS system files to drive C, then save the content in the master boot sector at this time (that is, the DOS boot information) to the C:\BOOTSECT.DOS file, which can be easily achieved with a small tool called SRC Tools in the "Disk Tools" on this site. Among them, SRCBOOT, SRCMBR, and SRCFAT are commands for saving, backing up, and comparing BOOT, MBR, and FAT respectively. The specific usage of the SRCTools toolset can be seen in the special article in the "DOS Articles" column. For example, SRCBOOT C: C:\BOOTSECT.DOS /S can save the boot sector of drive C to the C:\BOOTSECT.DOS file. At this time, the BOOTSECT.DOS file has been successfully established. Next, it's to restore the boot information of WinNT/2K/XP, which can be completed with the above BOOTPART tool, such as BOOTPART WINNT BOOT:C:. Then proceed with the following operation of modifying the BOOT.INI file.

Another method is to first save the boot information of WinNT/2K/XP to a file, then respectively establish the DOS system boot files and boot information, then use the above-mentioned SRC Tools to save the DOS boot information to the C:\BOOTSECT.DOS file, and finally restore the boot information of WinNT/2K/XP saved in the file to the boot sector. The specific process of establishing the DOS system boot files and boot information can be seen in the above method, and both saving and restoring the boot sector of WinNT/2K/XP can be done with the SRC Tools command. For example, you can respectively execute the commands SRCBOOT C: C:\NTBOOT.DAT /S and SRCBOOT C: C:\NTBOOT.DAT /R (the /S parameter means save, the /R parameter means restore, and NTBOOT.DAT is just a temporary file used for saving and restoring the boot information of WinNT/2K/XP, which can be deleted after completion), and then proceed with the following operations.

Finally, you can start making the dual-boot menu. The boot menu of WinNT/2K/XP is saved in the BOOT.INI file in the root folder of the primary boot partition (usually C:\BOOT.INI). The operation method is to first remove the read-only, hidden, and system attributes of the C:\BOOT.INI file (such as using the ATTRIB command自带 by DOS, or using the enhanced ATTRIB command, etc.), then open the C:\BOOT.INI file with a text editor (such as EDIT自带 by DOS), and add a line under the section in the file: C:\="MS-DOS". After completion, save the file and restore the various attributes of the file, then restart the system, and a boot menu will appear, which has the "MS-DOS" item. Select this item to enter the pure DOS mode. At this time, the dual-boot of WinNT/2K/XP and DOS is successfully made, and then you can select the corresponding boot option to boot the corresponding system.

This post also introduces how to solve the dual-boot problem.
http://www2.zzu.edu.cn/ie/newdos/dispbbs.asp?boardID=3&ID=46

But this post is the opposite operation, right!

Thanks, the dual-boot has been successfully set up.

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