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What is the BOOTREC /FIXBOOT access denied method of repair for MBR

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Thursday, March 8, 2018 7:30 AM

When using the command bootrec /fixboot it may display access denied.

  1. What is the method to fix bootrec /fixboot access denied for MBR?

bootrec /fixmbr displays:  The operation completed successfully

bootrec /scanos
Click enter to see (Scanning all disks for Windows installations; Please wait, since this may take a while.........Successfully scanned Windows installations. Total identified Windows installations: 0; The operation completed successfully) (This may display 0 or 1)

bootrec /rebuildbcd
Click enter to see (Scanning all disks for Windows installations; Please wait, since this may take a while.........Successfully scanned Windows installations. Total identified Windows installations: 0; The operation completed successfully) (This may display 0 or 1)

For each bootrec /scanow and bootrec /rebuildbcd the total identified Windows installations not in the BCD store were 0.

So to make sure the BCD is ok the following commands will be run:

bcdedit /export c:\bcdbackup
attrib c:\boot\bcd -h -r -s
ren c:\boot\bcd bcd.old
bootrec /rebuildbcd

Scanning all disks for Windows installations.
Please wait, since this may take a while...
Successfully scanned Windows installations.
Total identified Windows installations:  1
[1] D:\Windows
Add installation to boot list? Yes/No/All:
g) type:  Y
then enter key
It should display :
The operationi completed successfully. (The BCD rebuild is complete.)
h) reboot
https://www.lifewire.com/how-to-rebuild-the-bcd-in-windows-2624508

The MBR was fixed with bootrec /fixmbr
The BCD will be fixed with bootrec /rebuildbcd
2) How do you fix the partition boot sector when bootrec /fixboot displays access denied?
3) Should it no longer display access denied after the BCD is fixed with bootrec /rebuildbcd?  or should it have no impact?

  1. Would the command 
    bootsect /nt60 sys /mbr
    then be used to fix the partition boot sector?

  2. Please explain what rebuildbcd does and does not do to the partition boot sector.

  3. Please explain what bootsect /nt60 /mbr does and does not do to the partition boot sector.

  4. Should one or both make the bootrec /fixboot no longer display access denied and allow the fixboot command to work?

All replies (2)

Tuesday, March 13, 2018 7:54 AM

Hi,

If you encounter the access error when use bootrec /fixboot, we could try the suggestion by BillyBigun, it seems that the suggestion is useful for many customers. 

https://answers.microsoft.com/en-us/windows/forum/windows_10-update/windows-10-bootrec-fixboot-access-is-denied/747c4180-7ff3-4bc2-b6cc-81e572d546df

Bests,

Please remember to mark the replies as answers if they help.
If you have feedback for TechNet Subscriber Support, contact [email protected].

Tuesday, March 13, 2018 8:11 AM

That link was found early in the search and had multiple fix options however there were no explanations.

It had many see if it fixes or not without any explanations.

Instead of try this and try that without explanations this thread is to find/learn what to expect from each command.

For example how should bootrec /rebuildbcd impact fixboot /access denied?

How should bootrec /rebuildbcd impact the partition boot sector?

How should bootsect /nt60 sys /mbr impact fixboot /access denied?

How should bootsect /nt60.sys /mbr impact partition boot sector?

Can the partition boot sector be formatted and then rebuilt?  If so how is it done?  Are there any pitfalls?