Revisions to Fixing EFI Windows boot from Linux

added 320 characters in body

Source Link

edited Sep 6, 2021 at 21:15

1.9k
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56

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. Like, this should work:

menuentry "Windows 8 UEFI/GPT" {
    insmod part_gpt
    insmod search_fs_uuid
    insmod chain
    search --fs-uuid --no-floppy --set=root 28cf-35de
    chainloader ($root)/EFI/Microsoft/Boot/bootmgfw.efi
}

but I didn't try it turns out thatas I don't have much faith in grub2 and its documentation, but turned to the proper solution comes from Windows instead, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here are the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. but it turns out that the proper solution comes from Windows, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here are the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. Like, this should work:

menuentry "Windows 8 UEFI/GPT" {
    insmod part_gpt
    insmod search_fs_uuid
    insmod chain
    search --fs-uuid --no-floppy --set=root 28cf-35de
    chainloader ($root)/EFI/Microsoft/Boot/bootmgfw.efi
}

but I didn't try it as I don't have much faith in grub2 and its documentation, but turned to the solution from Windows instead, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here are the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

added 1 character in body

Source Link

edited Sep 6, 2021 at 15:10

xpt

1.9k
7
28
56

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. but it turns out that the proper solution comes from Windows, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here isare the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. but it turns out that the proper solution comes from Windows, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here is the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. but it turns out that the proper solution comes from Windows, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here are the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

Source Link

answered Sep 6, 2021 at 15:04

xpt

1.9k
7
28
56

OK, as per @FelixJN's request, here is the answer instead of a link.

My purpose was to seek a Linux based solution, as at least using ntldr loading Windows' bootmgr were the trick I used to use back in the old grub / grub4dos days. but it turns out that the proper solution comes from Windows, just as @telcoM summerized,

run the boot repair process in UEFI mode to write the Windows UEFI bootloader onto the ESP partition

Here is the details steps taken from here.

Insert the Media (DVD/USB) in your PC and restart.
Boot from the media.
Select Repair Your Computer.
Select Troubleshoot.
Choose Command Prompt from the menu :
1. Type and run the command :
```
diskpart
```
2. Type and run the command :
```
sel disk 0
```
3. Type and run the command :
```
list vol
```
Verify that the EFI partition (EPS - EFI System Partition) is using the FAT32 file system and assign a drive letter to it (Assign a letter that isn't already in use.):
Type and run the command :
```
 sel vol <number of volume>
```
Type and run the command :
```
 assign letter=<drive letter>:
```
Type and run the command :
```
 exit
```
In order to repair the boot record :
1. Type and run the command :
```
cd /d <drive letter>:\EFI\Microsoft\Boot\
```
2. Type and run the command :
```
bootrec /FixBoot
```

The next step is the same across all the operating systems at this point :

Rebuild the BCD store
First run the command below to backup the old BCD :
```
 ren BCD BCD.old
```

Now recreate it using this command :

 bcdboot c:\Windows /l en-us /s <boot letter>:All

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