How does Windows boot to advanced recovery option e.g. command prompt?

dalchina said:

It seems something went wrong in the original upgrade- as to what is impossible to say. It's a problem that doesn't seem amenable to being repaired; the bcd data doesn't seem to be updated appropriately when I click one of the advanced startup commands to cause the correct form of restart.

The odd thing is something is updated enough to cause the boot to hang once, until I power off. If I knew why that was, there might be a clue.

Of course, there are no diagnostic tools one could use during this sequence, which I wish I understood better. It seems the partitions are ok, but the earlier error messages (could not write bcd data e.g.) may have been misleading.

(And I agree with @cereberus this is probably not a QA issue, bar the questionable appropriateness of the error messages- a common problem with MS).

Does the command bcdedit /export <yourfilename> work for you? If not, you might have a problem similar to one I experienced. I'll post more details if that command fails.

dalchina said:

Hi, thanks, that works ok...

I guess you have a different problem than mine here Solution for Failed Windows 10 Update Installation Error 0x80004005

dalchina said:

My guess is that somewhere there's a partition id number discrepancy, but I've no idea where..

I had occasion to sort out booting to my recovery partition a while back. The GUID involved is the one shown by bcdedit as 'recoverysequence' for {current}. This should match the 'Boot Configuration Data (BCD) identifier' shown by reagentc /info

Somehow I'd managed to change mine and it was booting to a quite different recovery environment. I used reagentc to find the correct GUID and bcdedit to set it to boot correctly. This was back in Anniversary update, in case of further problems I kept a record of the information back then, and the updated information after the upgrade to Creators Update.

I've attached my records in case they are of help.

Interestingly, I've since discovered how my other system manages to boot to the recovery environment despite having no recovery partition (apparently the free upgrade to 10 was unable to find anywhere to put one, being an MBR which already had four partitions). The Windows RE location is shown by reagentc as:
\\?\GLOBALROOT\device\harddisk0\partition3\Recovery\WindowsRE

But partition 3 is my C: drive. The files that would normally be found in the recovery partition are instead in the hidden and inaccessible C:\Recovery folder, along with a 0 byte hidden file at the root of C: called $WINRE_BACKUP_PARTITION.MARKER

If the content is missing, why not do a clean install to a spare HDD then copy the files from the recovery partition it creates? Then put back your proper drive(s) and put the files into the empty recovery partition.

dalchina said:

However, what has persuaded me to discount the 480Mb recovery partition to date is its apparent lack of content...

What alerted me to my problem was that making a system image had stopped including the recovery partition in the images (that and the unfamiliar RE I was booting to). It appears that the reagentc and bcdedit info has to be correct for the system to know where to find (or in your case upgrade) the WinRE. I suspect yours was incorrect before the upgrade to Creators hence the lack of files being put into what you'd expect to be the recovery partition to be used.

I corrected mine before the upgrade to Creators, which did successfully upgrade my recovery partition. You can recognise a 1703 Advanced Start up by the white box around the selected option, 1607 and before didn't have that.