Forcing System boot up - Solved

[johncooool]

I will start by saying that I do not have a technical problem. I am trying to find a solution for an idea that I have. I am a Microsoft Windows technical support person and have no idea on how to work with this platform.

I have posted the 1st part of the thread in 2 other forums 2 days ago and got zero replies. After doing a lot of research I came to the conclusion that there is a high chance of finding a solution here.

Here is the request:

I am trying to boot Windows 7 or 8.1 that is on my HDD from another disc like a USB flash drive. The idea is to not allow windows to boot up unless the particular USB drive is plugged in to redirect the boot process. It is like a type of security.

I installed Wondershare Live boot and created a USB boot disk which has a Grub menu. It works fine, however, I edited the boot menu in the BIOS to stop HDD boot up and that stopped the process from working. I get error messages like "read error" or "Couldn't find the first disk sector". So I assume that stopping HDD from booting blocks the 1st boot sector of the disk.

I tried to edit the Grub menu from info I found on the internet and none of them worked.

I don't know if there is a way to bypass the BIOS restriction and to force boot up from the Grub menu.

The solution might be that I disable the boot process in a different way allowing the booting to occur only from the Grub menu.

Please don't suggest other security solutions. I want to learn this for expansion of knowledge.

The below link contains the post I posted in one of the other forums if anyone wants to take a look at it.

https://windowsforum.com/threads/use...ows-pc.246873/

[howefield]

Thread moved to the "Windows" sub forum.

[yancek]

Post the menuentry you use in Grub to attempt to boot windows. Also, post drive/partition information using the command: sudo fdisk -l (Lower Case Letter L in command)

I doubt that it will boot if you disable booting from the hard drive in the BIOS as Grub does not and never has directly booted windows the way it directly boots a Linux install. It chainloads to the boot partition of windows where the boot files exist so without that access, it won't boot.

Windows 7 is generally a Legacy install using code in the MBR while windows 8 is generally a UEFI/GPT boot with boot files on the EFI partition as well as the system partition. You obviously can install windows 8 on a Legacy (dos) drive rather than using UEFI/GPT.

One thing you might do is to set the usb to first boot priority in the BIOS and then create a BIOS password so this setting cannot be changed unless the user has that password. I'm not aware of any way to do exactly what you are looking for but someone else may have a suggestion.

[johncooool]

I have seen some videos on YouTube with windows booting from within Ubuntu O/S. So you are mistaken about your above comment.

Of course there is a way to launch it from Grub menu. As I mentioned above. It works before I disable the boot. We just need to figure a way around it. It is not necessary to do it by disabling the HDD from booting in BIOS. There might another way which then can be started by the Grub menu.

I do not understand the code you placed randomly as I have no experience on this platform.

Here is one of the codes I tried, the rest are deleted. It would either give an error that that map table is empty or that it can't hook.

hiddenmenu
default 0
timeout 4


Title Load Microsoft Windows Win7
map (hd0) (hd1)
map (hd1) (hd0)
map --hook
rootnoverify (hd0)
chainloader +1

title Reboot
reboot


title Back
chainloader /BOOTMGR

[johncooool]

I found a post from another forum were a person bypasses the BIOS to activate the CD-ROM. So I need something similar to that.

https://msfn.org/board/topic/153330-...solved/page/3/

[yancek]

I have seen some videos on YouTube with windows booting from within Ubuntu O/S. So you are mistaken about your above comment.

No, I am not. I imagine it is your limited knowledge of bootloading which is the problem. I would suggest you do an online search 'chainloading windows from Grub' so you understand the difference in directly booting and chainloading.

I do not understand the code you placed randomly as I have no experience on this platform.

What code? Are you referring to the fdisk command as that is the only 'code' I posted? That command has been around/used for 40 years and has been used on DOS and windows since the beginning and as I stated in my previous post, it is specifically used to list information on physical hard drives and partitions on them.

I'm not sure what "Wondershare" is as I have never heard of it prior to this post. Is this windows software using Grub4Dos as the link you posted shows using it?

The menuentry you posted to boot windows from Grub4DOS (or Grub Legacy, whatever you have) is incorrect as it needs to be pointing to a partition on which the boot files reside rather than the drive as a whole. Can't really give more specific information with the general information you have posted. Good luck.

[johncooool]

Do you have any suggestions for me to try.

To write a code in the same context of what is written above?

[QIII]

Nobody is asking you to "write a code". This is not a computer game.

Nobody asked you to "write code". You are doing no programming or software development.

You were asked to issue commands in a terminal emulator. This is exactly the same as a Windows technical support person might ask a Windows user to do after invoking cmd.

I would suggest that taking an antagonistic attitude towards a knowledgeable and technically proficient volunteer who, out of kindness to a newcomer, is trying to assist you might not be the best approach.

[oldfred]

If you want to understand how the old BIOS/MBR systems boot, this is one of the better links:
http://www.multibooters.com/guides/v...-sequence.html
http://www.multibooters.co.uk/multiboot.html
http://www.multibooters.com/

Of course since Microsoft required vendors to install Windows 8 in UEFI boot mode with gpt partitioning in 2012, most systems are UEFI. But a user can install even Windows 10 in BIOS boot mode.
UEFI https://wiki.archlinux.org/index.php...ware_Interface
http://www.rodsbooks.com/efi-bootloaders/

Since as shown in above BIOS boot, Windows uses boot flag to find partition with boot files, but grub uses os-prober and looks for the partition with the required Windows boot files and creates a chainload to the Windows PBR - partition boot sector to boot. It does not boot Windows directly.

Some examples:
Windows 7 entry with 100MB initial partition
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/sda1)" {
insmod ntfs
set root=(hd0,1)
search --no-floppy --fs-uuid --set 2ae000d2e000a663
chainloader +1
}
### END /etc/grub.d/30_os-prober ###

alternate to chainloader +1
ntldr /bootmgr

Two changes were made to the commands in (3) versus (4).
The new command insmod ntldr was added.
The command chainloader +1 was replaced with ntldr ($root)/bootmgr
added insmod ntldr and change chainloader +1 to ntldr ($root)/bootmgr, and it works wonders!

the map command is often required if BIOS not booting same drive as Windows. Windows expects to be first in most cases, so the map switches the boot drive, so Windows still thinks it was the drive booted.

#If not hd0,1
menuentry "Windows 7"
{
insmod ntfs
set root=(hd0,1)
drivemap -s (hd0) ($root)
ntldr /bootmgr
#or chainloader +1
}

[johncooool]

If you want to understand how the old BIOS/MBR systems boot, this is one of the better links:
http://www.multibooters.com/guides/v...-sequence.html
http://www.multibooters.co.uk/multiboot.html
http://www.multibooters.com/

Of course since Microsoft required vendors to install Windows 8 in UEFI boot mode with gpt partitioning in 2012, most systems are UEFI. But a user can install even Windows 10 in BIOS boot mode.
UEFI https://wiki.archlinux.org/index.php...ware_Interface
http://www.rodsbooks.com/efi-bootloaders/

Since as shown in above BIOS boot, Windows uses boot flag to find partition with boot files, but grub uses os-prober and looks for the partition with the required Windows boot files and creates a chainload to the Windows PBR - partition boot sector to boot. It does not boot Windows directly.

Some examples:
Windows 7 entry with 100MB initial partition
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/sda1)" {
insmod ntfs
set root=(hd0,1)
search --no-floppy --fs-uuid --set 2ae000d2e000a663
chainloader +1
}
### END /etc/grub.d/30_os-prober ###

alternate to chainloader +1
ntldr /bootmgr

Two changes were made to the commands in (3) versus (4).
The new command insmod ntldr was added.
The command chainloader +1 was replaced with ntldr ($root)/bootmgr
added insmod ntldr and change chainloader +1 to ntldr ($root)/bootmgr, and it works wonders!

the map command is often required if BIOS not booting same drive as Windows. Windows expects to be first in most cases, so the map switches the boot drive, so Windows still thinks it was the drive booted.

#If not hd0,1
menuentry "Windows 7"
{
insmod ntfs
set root=(hd0,1)
drivemap -s (hd0) ($root)
ntldr /bootmgr
#or chainloader +1
}

It seems that we are getting closer and it seems that you have correct understanding of my request.

I tried your examples and none of them worked. I got Error 8 (Kernel must be loaded before booting) with the last code that you game me.

Please give me more tips and more examples to try out.

WINDOWS 7 is installed on the 2nd partition because the 1st one is recovery partition. No UEFI on that device.

Thanks