Context: Windows 10 Pro, updates until 1 October 2016 applied running on a machine with UEFI boot.
Machine was original a Windows 8.1 machine but was upgraded many months ago to Windows 10. Bitlocker is not enabled.
The restart following the October updates hang with those dots going round and round for hours. Eventually after several hours I powered off the PC, but unfortunately on restart I got a /BCD missing error code: 0xc0000098 and entered the repair life cycle.
I started troubleshooting using a USB Recovery Driver with simple Advanced Options | Startup Repair but that failed to repair the start-up. I then progressed to command line options. Looking at the C: drive all appeared OK, BCDEDIT showed a BCD that looked fine and CHKDSK didn’t show any errors. I tried
- bootrec.exe /ScanOs
- bootrec.exe /fixmbr
- bootrec.exe /fixboot
- bootrec.exe /RebuildBcd
but no OS was found, though the C:\windows directory appeared intact.
Checking around further I found a different approach might be need for UEFI boot (https://hetmanrecovery.com/recovery_news/repairing-windows-boot-loader.htm) . The technique is shown appears on numerous other sites. I followed the instructions and added the verbose switch on BCDBOOT to get a clearer picture of what was going on. This culminated in:
m:\EFI\Microsoft\Boot>ren BCD BCD_2016-10-29B.bak
m:\EFI\Microsoft\Boot>bcdboot c:\Windows /s M: /f ALL /v
BFSVC Error: Failed to open file c:\Windows\boot\PCAT\bootmgr for read! Error code = 0x780
BFSVC Error: Failed to validate boot manager checksum (c:\Windows\boot\PCAT\bootmgr)! Error code = 0xc1
Failure when attempting to copy boot files.
Checking bootmgr using ATTRIB the file the symbolic links points to appears to be missing.
The target of the symbolic link C:\windows\boot\PCAT\bootmgr does not exist
I checked the same ATTRIB command on a bootmgr from a working machine and it return attributes as expected.
I have no idea and cannot find out on Windows 10 what the file c:\windows\boot\PCAT\bootmgr actually links to and should link to. So I have no way of checking to see if the file is missing and the link needs recreating, or if the link is correct and somehow the file it points to has been deleted. At this point, prior to starting a full rebuild, I thought I’d check with the community since I see others have had similar but not the same experience.
- In Windows 10 what is the target of the symbolic link C:\windows\boot\PCAT\bootmgr ? Ideally a pointer to a definitive detailed description of the boot process in Windows 10.
- Any suggestions on steps to take to get the machine to boot the windows installation on the C: drive?
If you have got this far, thanks for reading and hope you can help