Onedrive seems to have created its own drive G partition and moved my previous drive G partition to drive L

The BCD (Boot Configuration Data) is a file that contains information critical to a successful boot, like the locations of the boot files (normally in EFI) & of the Windows & Recovery partitions. Yours gets the job done apparently, but is abnormal in that it has no {bootmgr}, & it has duplicate & unused sections. I'm unsure Windows can pass messages through yours as sometimes it will do during a reboot to complete an install.

It's OK to mess with the BCD so long as you back it up first. Also, you must have the means to restore the backup. You've got that Recovery partition & it has its WinRE.wim -- but you never answered whether Shift+Restart will get you there. But, actually, the current BCD will be unavailable once renamed. The new one would have to work for that. And I'm unsure whether a bad BCD prevents Windows from getting there through other means, like the 3 shutdown method or the error message.

I think it best you make a Repair Disc, Recovery USB drive or Win 10 Installation media before messing with the BCD. Want instructions?

Hi PCR...

thanks for this detailed step by step. But before I follow it can you please explain to me what is the BCD and why I need it? What would I be trying to accomplish following your detailed instructions?

Cheers!

Garry

Deleted & reposted as I recalled Bootrec exists only in the recovery environment.

You are welcome. Bootrec only exists in the recovery environment. It's really best to have a Recovery drive or Installation media to get there in this circumstance. Do you have one? Those have an external recovery environment onboard. Otherwise...

(a) Hold Shift as you click Restart to get to the internal recovery environment.

(b) Click "Troubleshoot > Advanced Options > Command Prompt".

(c) Enter the following commands...

DiskPart <<<Enter DiskPart

List Vol <<<List the volumes & their letters

Exit <<<Exit DiskPart

=== You should recognize the Windows volume by its label or size ===

=== Note its letter which may not be C: in this environment ===

=== Use that letter instead of X: in the following commands ===

MD X:\BU <<<Make a folder on "C:" named BU

BCDEdit /Export X:\BU\BCD_Backup <<<Backup the BCD into it

DiskPart <<<Enter DiskPart

Select Disk 0 <<<Focus on disk 0

List Part <<<List the partitions

Select Part 2 <<<Focus on partition 2 (EFI System)

Assign Letter=S <<<Give it letter S:

Exit <<<Exit DiskPart

REN S:\efi\microsoft\boot\bcd bcd_old <<<Rename current BCD

Bootrec /RebuildBCD <<<Create fresh BCD

DiskPart <<<Enter DiskPart

Select Vol=S <<<Focus on EFI

Remove Letter=S <<<Remove the letter

Exit <<<Exit DiskPart

That should do it. Close the Command Prompt, & click "Continue" to return to Windows. At an Admin Command Prompt, enter...

BCDEdit /Enum All <<<Show the new BCD

Use Ctrl-A & Ctrl-C to copy, then post it here. I'm unsure the Recovery partition will have activated so that Shift+Restart will continue to work. If not, we can then activate it manually.

If it won't reboot, get into the recovery environment...

(a) An error message may have an "Advanced Options" button that gets there.

(b) Shut the computer 2 times as it tries to boot. On the 3rd attempt to boot it should go there.

(c) Use a Recovery drive or Installation media to get there. Need instructions?

Then, at the "Choose an Option" screen...

(a) Click "Troubleshoot > Advanced Options > Command Prompt".

(b) Enter the following commands...

DiskPart <<<Enter DiskPart

List Vol <<<List the volumes & their letters

Exit <<<Exit DiskPart

=== You should recognize the Windows volume by its label or size ===

=== Note its letter which may not be C: in this environment ===

=== Use that letter instead of X: in the following command ===

BCDEdit /Import X:\BU\BCD_Backup /Clean <<<Restore the backup BCD

Close the Command Prompt, & click "Continue" to return to Windows.

Hi PCR....

Am trying to follow what your are saying about the BCD?

"I don't know, maybe we should let it be, but I'm inclined to want to regenerate your BCD. Here is what mine looks like...

(a) {bootmgr} is on top in the Firmware Boot Manager.

(b) There are no duplicate, malformed or unused sections.

Microsoft Windows [Version 10.0.19043.1288]

(c) Microsoft Corporation. All rights reserved.

*C:\Windows\system32>*bcdedit /enum all

Firmware Boot Manager "

there is a lot of information after this that I have no idea what it is all about or where or how it is produced.

If I am to create a new BCD can you walk me through the steps please, as you did withthe previous part. Where to start and what to do.

thansk again.

Garry