China DOS Union

It has been like this: both primary partitions are in FAT format, 518MB, and currently the first partition is active.
title DOS/Win9x on (hd0,0)
root (hd0,0)
chainloader +1
title DOS/Me/2K on (hd0,1)
rootnoverify (hd0,1)
chainloader +1

It freezes when selecting the second item!
If you add makeactive, it returns an error message.
I think: Although the second partition is not active, but hd0,1 means it's okay?

I saw such a writing on the Linux Knowledge Base website; could it be that those who play Linux didn't test on MS machines?

Additionally: Ask about whether the compile files, patch, and files ending with 1-5 are necessary? Do I have to compile them myself?

The causes of system freeze are that Windows gets into a muddle (I don't know what version of Windows you are using).

When a primary partition is activated, Windows may try to treat it as drive C:, which may cause confusion.

GRUB has several specific commands to deal with this situation, such as makeactive, hide partition, etc. You can study them first.

Typing the info grub command under Linux can view detailed explanations of GRUB commands.

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If you don't compile, you won't be able to use those files. They are for those who look at the source code by themselves.

You only need grub.exe (under DOS), or only one file GRLDR is enough (under NT/2K/XP)

The hide and unhide commands? I've tried it! hide (hd0,0) hides the first partition; unhide (hd0,1) shows the second partition; is it used like this? The result of practice is: the first partition is hidden, but the second partition is still hidden! The original D drive on the machine has become the C drive. The reason for the crash is: the current C drive is not a bootable partition. Could it be that GRUB can't display partitions hidden by PM? It seems there are no other GRUB commands to handle this problem?! Also: later I opened PM to display a partition, and found that the first partition is still marked as: ACTIVE——It is said that there must be a primary partition in the displayed state, how can both primary partitions be hidden?

The day before yesterday, I was operating in the GRUB command line with the second partition activated. At that time, I attempted to boot the system of the first partition and used the commands hide (hd0,1) unhide (hd0,0). As a result, the boot was not successful. It was found that the first partition was already visible, but the second partition was not hidden. Then I repeated the operation twice, and suddenly all the extended partitions disappeared!

In a panic, I mistakenly used a tool that does not support multiple primary partitions to repair, and the partition was damaged even more. Later, it took me almost a whole day to retrieve the loss.

Now I want to ask: Both times above were failures in handling the second primary partition, while the same operation on the first primary partition was completely normal. Is this a problem with GRUB?

Could it be that my question is too simple? No one pays attention~

It is possible that (hd0,1) is an extended partition rather than a primary partition. First, type "(hd0," and then press the Tab key to check.

I don't dare to say that GRUB is fine. But your own problem may be the main one.

If you only use hide/unhide, your partitions won't be damaged.

I guess your extended partition may have been hidden by you, so it seems to be gone.

Your problem is really not very complicated. As long as you are more careful, you can solve it by yourself.

My mistake! hd(0,1) is indeed an extended partition! Now I finally understand that the partition table is arranged like this: the first primary partition, extended partition (second primary partition, third primary partition), and other logical partitions... It took so much effort to figure it out, it's really hard-won!