China DOS Union

The so-called setting to boot from the third hard disk in BIOS, I feel that its implementation principle is the same as the disk swapping with the map command in Grub. This is only a BIOS-level setting, but under NT, this setting is invalid. Therefore, do not modify the Boot.ini setting of NT. As long as the NT boot menu can appear, it can start NT normally according to the original setting. However, if your original NT was installed as the second primary partition of the first hard disk, it will still start abnormally because NT will remember its installation partition. The solution is to delete all contents under hklm\system\mounteddevices.

Originally posted by Climbing at 2006-8-15 08:59 AM:
The so-called setting to boot from the third hard disk in BIOS, I feel its implementation principle is the same as the map command in Grub to swap disks. This is only a BIOS-level setting, but in NT, this setting is invalid, so...

The third hard disk in BIOS is indeed the same as the map in Grub, but in boot.ini, the disk number should be written as rdisk(0) instead of rdisk(2), because during the NTldr stage, the map command is valid until NT starts to a certain stage (probably after the keyboard three lights flash), and then the NT disk driver takes effect and the map command becomes invalid.

I once used the map to swap disk numbers, then loaded the ntldr and boot.ini on the second hard disk to boot XP on the second hard disk. After booting, the system showed that the boot partition was the first partition of the second hard disk.

Thanks to brother fujianabc for the correction. In short, this problem should not be considered a very complicated one.

Well, it might be as CLIMING said, but:
I don't want to use WINPE (time-consuming). The question is: How to open the registry of the XP partition that can't boot?
(Can I use the normally booted XP to open the registry of my unbootable XP partition?)

My GRUB can use
chainloader (hd2,1)/bootsect.dos

But can't use
chainloader (hd2,1)/ntldr

I find it very strange!

Your grldr has an extraction error.

Originally posted by GOTOmsdos at 2006-8-15 10:08 AM:
Well, it might be like what CLIMING said, but:
I don't want to use WINPE (it takes time). The problem is: How to open the registry of the unbootable XP partition?
(If I can use the normally booted XP to open my ...

There seems to be some problem with uploading attachments here. Try this:
http://zhenlove.com.cn/cndos/fileup/files/grldr.rar

But, this should be executed by boot.ini, and boot.ini is executed by ntldr, right?

The solution is to delete all contents under hklm\system\mounteddevices.

Just now, I have booted BARTPE: used the above method, but it didn't work. I also tried deleting the entire hklm\system\mounteddevices sub-item itself.
The error prompt is still the same: NTLDR IS MISSING...
(And this hard drive has already been plugged into the first hard drive position)

If you have already plugged it into the first hard disk, first try the fixboot command of the fault recovery console to repair the boot sector.