Windows 10 error code 0xc00000 bootcamp partition

Use a USB2 flash drive of 8+GB (USB3 will not work), and a W10 ISO from Download Windows 10 Disc Image (ISO File)

and Build your own Windows 10 Bootcamp USB Installer . Once booted, you will need to use diskpart to find the drives for Bootcamp (typically C:) and the System drive (S:, but this may not be assigned).

Use bcdboot to rebuild the BCD.

This happened to me, all I had to do is reinstall Mac OS then I selected the same Hard Drive (Partition) that my existing Mac OS was on. When it booted back up into the Mac OS my existing account, files and applications were all fine. The only thing now, I must boot my system by holding down the Option key to select from the Mac OS Partition or the Windows OS Partition. Since BootCamp setting in Windows will not allow me to boot from anything other then Windows since selecting the Mac OS causes and error message. (This error message is only a pop up that shown while in Windows). The good news if you go into the Preference Setting while in Mac OS, you can then use the Startup Disk to select which OS to startup from.

Wait, you're right. Windows didn't boot for me either. I remember. I had to boot using my Windows 10 Install USB drive to reinstall Windows 10. But I did need to reinstall Mac OS first. I used the Option key during boot up and I selected the Window Install USB. I had to delete the previous partition I had Windows on during the installation process. But I was able to use my back up I had for Windows to get back my settings and previous, documents and applications. It's been working just fine since and that addition partition was extended (added) to my Bootcamp partition. I was lucky I didn't have to use any advance steps to repair my Mac since from the beginning I selected the partitioning method from Disk Utility while in the Mac OS. Perhaps that's the reason it worked out for me.

If the Diskpart mapping does not show the shared EFI partition/volume, you may want to consider re-installing Windows. Re-installation, without formatting the partition will save your old installation in Windows.old.

If you have a System Image created via Windows Backup/Restore, another possibility is to remove the current partition via BCA, re-install Windows and and then use a System Restore.

Be aware, that all options are now risky and can result in further data loss. Does bcdboot not work correctly? You can always specify C: as the BCD and the System volume.

You are manipulating partitions which is not supported. Your 2015 model only supports EFI Boot, and the error indicates BCD corruption. Do you have a backup of macOS and Windows?

See the steps in Use Bootrec.exe in the Windows RE to troubleshoot startup issues . You must be on C: to run /fixBoot.

karofromgöteborg wrote:

So after this precidure of resizing a partition is the case of BCD issues normal?

I did this on an earlier Mac OS before the new diskutily layout and didn’t have any issues at all.

On 2013 and later Macs, if you have EFI Boot, BCD corruption is normal, because you have changed the partition table, underneath Windows. On older Macs with Hybrid MBRs, the extent of the issue depends on what is done to the GPT and MBR.

karofromgöteborg wrote:

If Mac OS installs and boots properly is there any chance to repair the windows partition to boot or do I need to reinstall windows? I’m a bit worried about that my image backup somehow doesn’t work properly.

We can try to recover the existing partition, fall back to the System Image or re-install Windows, in that order.

See BCDEdit Command-Line Options , and specifically the /store and /sysstore qualifiers. If you cannot find the BCD, on my 2012 MBP with BIOS mode installation, it can be seen from the macOS side as

cd /Volumes/BOOTCAMP/

ls -lg Boot/

BCD cs-CZ/ fr-CA/ nb-NO/ sr-Latn-CS/

BCD.LOG da-DK/ fr-FR/ nl-NL/ sr-Latn-RS/

BCD.LOG1 de-DE/ hr-HR/ pl-PL/ sv-SE/

BCD.LOG2 el-GR/ hu-HU/ pt-BR/ tr-TR/

BOOTSTAT.DAT en-GB/ it-IT/ pt-PT/ uk-UA/

Fonts/ en-US/ ja-JP/ qps-ploc/ updaterevokesipolicy.p7b

Resources/ es-ES/ ko-KR/ ro-RO/ zh-CN/

bg-BG/ es-MX/ lt-LT/ ru-RU/ zh-HK/

bootspaces.dll et-EE/ lv-LV/ sk-SK/ zh-TW/

bootvhd.dll fi-FI/ memtest.exe sl-SI/

ls -lg Boot/BCD

-rwxr-xr-x@ 1 staff 49152 May 11 18:26 Boot/BCD

You can also use

dir/s/p to look for BCD on C:. X: is your external boot media. Rebuilding BCD on X: does not address any issues. You can skip the export step, if necessary.

Also, see windows - Recover Bootcamp EFI Folder/fix boot entries? - Ask Different .

Are you running /fixboot on C:?