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bootsect /nt60; format /fs:fat32; md\efi\microsoft\boot; bcdboot c:\windows /L en-us /s all and other command line switches to fix boot problems

Question

Sunday, February 18, 2018 10:55 AM

Assume the standard commands to fix a boot fail:

bootrec /fixmbr

bootrec /fixboot

bootrec /scanos

bootrec /rebuildbcd

What are the various types of boot failure or how do you separate them into a few categories so that you can organize the troubleshooting steps?  

Which methods are indicated for the various types of boot failure:

1) When is bootsect /nt60 c: used?

2) When bootrec /fixboot displays access denied what are the various fix methods?

a) When does the EFI volume need or not need to be formatted? (/fs:fat32)

b) When does the bcdboot c:\windows /L en-us /s need to have or not have the switch /f ?

What is the difference between these commands?

The FAT 32 volume has been labeled W using diskpart (assign letter=W)

a) Format W: FS:FAT32

b) MD \EFI\Microsoft\boot

c) cd /d W:\efi\microsoft\boot

d) bootrec /fixboot

e) bcdboot c:\windows /L en-us /s W:/F all

versus

a) cd /d W:\efi\microsoft\boot

b) bootrec /fixboot

c) ren bcd bcd.old

d) bcdboot c;\windows /L en-us /s W:all

Notice the first one had a format where as the second one had a rename and did not have a /F.

If a format is done does that impact the other commands such as bootrec /rebuildbcd or bootrec /fixmbr?

If bootsect /nt60 C: is used which other commands does this command impact?  Does it impact bootrec /rebuildbcd or bootrec /fixmbr or bootrec /fixboot?

On a clean install the command bootrec /rebuildbcd displayed 0 additional copies of windows.  For a computer that fails to boot the rebuildbcd can also display 0 additional copies of windows.  So when bootrec /rebuild displays total identified windows installations: 0 how do you know whether or not it needs to be fixed?

How do you know when to use:

bcdedit /export c:\bcdbackup

attrib c:\boot\bcd -h -r -s

ren c:\boot\bcd bcd.old

bootrec /rebuildbcd

Total identified Windows installations:  1
[1] D:\Windows
Add installation to boot list? Yes/No/All:

A

What does it mean if the command bcdedit /enum displays the boot configuration data store could not be opened?  The requested system device could not be found.  Which part of the boot is misconfigured or corrupt?  Which part needs to be fixed?  Is a format of the EFI volume needed?  What does bootsect /nt60 c: do in this circumstance?

What does it mean if the command bcdedit | find "osdevice" does not display a response?  Which part of the boot is misconfigured or corrupt?  Which part needs to be fixed?  IS a format of the EFI volume needed?  What does bootsect /nt60 C: do in this circumstance.

Please explain the different parts of the boot and which parts don't need to be fixed if another command is used and please explain how each part can be fixed individually.

If you have an unknow boot problem with failure to boot and want to fix the boot which of the above steps takes care of any of the boot problems as one step and which of the above steps can be put together to fix all part of the boot (that is when there is access denied or identified windows installations=0?

There are registry hives that can fix part of the boot.  How do you know whether or no to use a registry backup or a registry repair when troubleshooting boot problems?

All replies (2)

Monday, February 19, 2018 4:52 AM

Hi,

As far as I know, run the "Bootsect.exe /nt60 G:" command to put boot manager compatible files onto your USB flash drive to make it a bootable device.

BCDBoot Command-Line Options

/en-us/windows-hardware/manufacture/desktop/bcdboot-command-line-options-techref-di

Hope it will be helpful to you

Please remember to mark the replies as answers if they help.
If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.


Monday, February 19, 2018 8:31 AM

There are many threads with failure to boot.

The failure to boot have many causes.

There are multiple methods to fix depending on whether the cause is know or not know.

In most of these cases the cause was not known.

So all of these questions are in general questions and will help anyone viewing the questions and answers.

There are no questions about flash drives.  All questions are about HD or SSD with Windows 10 that fail to boot with the 4 standard commands.

They are general questions about the tools, commands, and switches available to fix boot problems.

The OP was organized with numbers.

Please follow in kind with numbers so that the answers can be followed for each question.

Assume the standard commands to fix a boot fail:
bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

  1. What are the various types of boot failure or how do you separate them into a few categories so that you can organize the troubleshooting steps?  

  2. Which methods are indicated for the various types of boot failure:

  3. When is bootsect /nt60 c: used?

  4. When bootrec /fixboot displays access denied what are the various fix methods?

  5. When does the EFI volume need or not need to be formatted? (/fs:fat32)

  6. When does the bcdboot c:\windows /L en-us /s need to have or not have the switch /f ?

  7. What is the difference between these commands?

The FAT 32 volume has been labeled W using diskpart (assign letter=W)

a) Format W: FS:FAT32

b) MD \EFI\Microsoft\boot

c) cd /d W:\efi\microsoft\boot

d) bootrec /fixboot

e) bcdboot c:\windows /L en-us /s W:/F all

versus

a) cd /d W:\efi\microsoft\boot

b) bootrec /fixboot

c) ren bcd bcd.old

d) bcdboot c;\windows /L en-us /s W:all

Notice the first one had a format where as the second one had a rename and did not have a /F.

  1. If a format is done does that impact the other commands such as bootrec /rebuildbcd or bootrec /fixmbr?

  2. If bootsect /nt60 C: is used which other commands does this command impact?  
    a) Does it impact bootrec /rebuildbcd or bootrec /fixmbr or bootrec /fixboot?

  3. On a clean install the command bootrec /rebuildbcd displayed 0 additional copies of windows.  
    For a computer that fails to boot the rebuildbcd can also display 0 additional copies of windows.  
    So when bootrec /rebuild displays total identified windows installations: 0 how do you know whether or not it needs to be fixed?

  4. How do you know when to use:

 bcdedit /export c:\bcdbackup

 attrib c:\boot\bcd -h -r -s

 ren c:\boot\bcd bcd.old

 bootrec /rebuildbcd

Total identified Windows installations:  1
[1] D:\Windows
Add installation to boot list? Yes/No/All:

A

  1. What does it mean if the command bcdedit /enum displays the boot configuration data store could not be opened?  
    a) The requested system device could not be found.  
    b) Which part of the boot is misconfigured or corrupt?  
    c) Which part needs to be fixed?  
    d) Is a format of the EFI volume needed?  
    e) What does bootsect /nt60 c: do in this circumstance?

  2. What does it mean if the command bcdedit | find "osdevice" does not display a response?  
    a) Which part of the boot is misconfigured or corrupt?  
    b) Which part needs to be fixed?  
    c) Is a format of the EFI volume needed?  
    d) What does bootsect /nt60 C: do in this circumstance.

  3. Please explain the different parts of the boot and which parts don't need to be fixed if another command is used and please explain how each part can be fixed individually.

  4. If you have an unknow boot problem with failure to boot and want to fix the boot which of the above steps takes care of any of the boot problems as one step and which of the above steps can be put together to fix all part of the boot (that is when there is access denied or identified windows installations=0?

  5. There are registry hives that can fix part of the boot.  
    How do you know whether or no to use a registry backup or a registry repair when troubleshooting boot problems?