Acer Aspire SW5-012 boot error 0xc0000185 (error in BCD)

wisekat

I have an Acer Aspire tablet SW5-012 with the preinstalled Windows 8.1. I have used it without any problems for years, but something bad happened to it a couple of months ago. If I try to boot my tablet, I see a error message from the Windows Boot Manager. It's a DOS screen with the BCD error 0xc0000185:



I can pass this screen and boot into Windows via some manipulations by booting into the UEFI BIOS via the Windows key, but all this is unpredictable and may require much time because of many unsuccessful tries.

I thought I could repair the pc from Windows using its reset feature or boot into WinRE to fix the BCD records, but it is not possible. Windows simply does not provide these tools. Ok. I downloaded a clean Windows 8.1 ISO installation from the Microsoft website, wrote it to a flash drive using Rufus and booted from it into WinRE. Then executed the following commands:

bootrec /fixmbr

bootrec /fixboot

bootrec /scanos

bootrec /rebuildbcd

This didn't help. The problem still persists.

I found the preinstalled Acer Recovery Management app on C: after booting into Windows and tried to restore the factory installation with it, but this app simply hangs and does nothing

I also created a recovery flash drive using Acer Recovery Management. Then tried to boot from this drive but got this:



Other methods to repair my tablet like Alt+F10 of Power+Windows keys at boot do not work.

I also run 'sfc /scannow' in the command prompt window launched with admin privileges, and it reported a problem with my system files. However, I could not fix them with the Windows DISM tool (by running 'dism /online /cleanup-image /restorehealth').

What can I do else to repair my pc myself?

JackE

>>>but something bad happened to it a couple of months ago. I>>>

>>>bootrec /fixmbr

bootrec /fixboot

bootrec /scanos

bootrec /rebuildbcd>>>

This method is for a legacy BIOS  with an MBR partitioned boot disk, NOT a UEFI bootstrapper with a GPT-partitioned boot disk. After all the fixes you've tried to apply on the disk, it's hard to determine  what state it's in now.

So I have to ask you if you have any idea of what the "something bad" was? If it happened for no apparent reason, then my best guess is that the HDD read/write head crashed against the disk platter in the partition where the trusted EFI file is located.

I suggest that you try to re-make the Win8.1 installation USB using the Microsoft tools at this link

If for some reason you must use the iso, then make sure the Rufus USB is set for GPT partition scheme, FAT32 formatted for a UEFI non CSM bootstrap. 

 

 

wisekat

I can't say with certainty what event preceded the BCD corruption.
As for bootrec, I think 'bootrec /fixmbr' simply did nothing because it is applicable only to MBR partitioned drives. At least, I still see the Windows Boot Manager error screen as earlier - which confirms that the bootloader works, agreed?
And I already re-made the Win8.1 installation USB. Actually I've written that I could enter WinRE using this flash drive.
BTW, I also tried to install Windows using this USB, but the process stopped in the beginning on the Enter Serial Number screen. The s/n must be in the motherboard and the installer could detect it, but this does not happen.
Any thoughts what can I do else?

JackE

>>>BTW, I also tried to install Windows using this USB, but the process stopped in the beginning on the Enter Serial Number screen.>>>

Are you sure it's asking the the machine's serial number? It might be looking for the Windows ACER OEM license number. This should be on a label on the bottom or UPC label on the original package.

At any rate, can you access the BIOS to set and save a supervisor password? Then re-enter the BIOS with the password to disable secure boot?

wisekat

I meant the Windows key (25 numbers/letters). But neither my tablet itself nor its detachable keyboard have it anywhere. Any ideas how to find it or request from Acer?

Well, I found the article that partially helped me to solve the problem for my GPT/EUFI situation:
http://woshub.com/how-to-repair-uefi-bootloader-in-windows-8/

I rebuilt my BCD using the following command:
bcdboot C:\Windows /l en-us /s k: /f UEFI

Now I see the same DOS error screen from Windows Boot Manager during boot. However, if I press the Windows key on the tablet, I can enter BIOS and then simply exit it without saving changes. This always allows me to load my Windows.

Have any new ideas?

JackE

If you're into Windows now, go to the elevated command prompt. Enter 'wmic os get serialnumber'. The result should be the Windows OEM key.

wisekat

'wmic os get serialnumber' returns a 20-character code, but the Windows installer does not accept it. It expects a 25-character key...

JackE

Does it have an OEM in the string?

wisekat

Yes, it ends with 'AAOEM' . 

JackE

What problem are you having with your system right now that you want to try to fix?

billsey

Best is likely to just rebuild the EFI partition, it seems to be corrupt. From your WinRE command prompt use diskpart to assign a letter (<boot letter>) to the EFI partition. Then try:

ren BCD BCD.old<br>

from that boot directory and

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

That should rebuild the BCD and get you running correctly again. You can then remove the drive letter for the EFI partition so it doesn't accidentally get mucked with again.

wisekat

billsey, this is exactly what I did. Re-read my post in which I refer to woshub.com.

JackE and all. The last thing I did on Friday (Jan-14) was this:

<span>bootrec /fixboot</span><span><br>bcdboot c:\Windows /s K: /f UEFI<br></span>

The tablet was functioning properly about that. I was using it for a long time on Saturday. I could reboot about a dozen of times, using the shutdown or restart command in Windows, and all was ok.

However, today, on Monday Jan-17, the problem suddenly appeared again at the first time when I turned my tablet on. What it could be? Perhaps, a hardware problem?

JackE

>>>The tablet was functioning properly about that.>>>

Re-do the bcdboot command but Immediately before doing it, run

bootrec /FixBoot

bcdboot C:\Windows /l en-us /s k: /f UEFI --- or --- bcdboot c:\Windows /l en-us /s k: /f All

 

wisekat

I meant the Windows key (25 numbers/letters). But neither my tablet itself nor its detachable keyboard have it anywhere. Any ideas how to find it or request from Acer?

Well, I found the article that partially helped me to solve the problem for my GPT/EUFI situation:
How to Repair EFI/GPT Bootloader on Windows 10? | Windows OS Hub (woshub.com)

I rebuilt my BCD using the following command:
bcdboot C:\Windows /l en-us /s k: /f UEFI

Now I see the same DOS Windows Boot Manager error screen during boot. However, if I press the Windows key on the tablet, I can enter BIOS and then simply exit it without saving changes. After doing this, my Windows always loads without any problems.

Any new ideas?

wisekat

I meant the Windows key (25 numbers/letters). I can't find it anywhere on my tablet or the detachable keyboard.

I found an article describing how to rebuild the BCD for GPT/UEFI:
How to Repair EFI/GPT Bootloader on Windows 10? | Windows OS Hub (woshub.com)
And it seems, it works!!

A quick recap. I needed to delete the existing BCD configuration and then issue the following command in WinRE:
bcdboot C:\Windows /l en-us /s k: /f ALLRead the article for more details.