Windows Server 2012 R2 Boot Repair -

bootsect /nt60 sys /mbr A corrupted SYSTEM registry hive breaks boot with errors like 0xc000021a or 0xc0000034 . The recovery environment allows you to replace it with a backup copy.

Introduction: The Critical Nature of a Server That Won’t Boot windows server 2012 r2 boot repair

The most important takeaway is never to panic and never to format and reinstall as a first response. That last resort wipes configuration, roles, and data. With the commands and techniques outlined in this guide, you can repair the boot process on Windows Server 2012 R2 in 90% of cases without losing your server’s identity and data. bootsect /nt60 sys /mbr A corrupted SYSTEM registry

| Error Code | Likely Cause | Quick Fix Method | |------------|--------------|------------------| | 0xc000000e | BCD corruption | Method 2 | | 0xc000000f | Bootmgr missing | Method 2 (fixboot) | | 0xc0000225 | Partition issues | Method 2 + diskpart active partition | | 0xc000021a | Registry corruption | Method 4 | | INACCESSIBLE_BOOT_DEVICE | Storage driver | Method 7 | | 0xc0000034 | Boot file missing | Method 2 (rebuildbcd) | That last resort wipes configuration, roles, and data

Sometimes bootrec /rebuildbcd fails with "Element not found." Use BCDEdit:

bcdedit /createstore C:\boot\bcd bcdedit /store C:\boot\bcd /create /d "Windows Server 2012 R2" /application osloader (Note the GUID returned) bcdedit /store C:\boot\bcd /set GUID device partition=C: bcdedit /store C:\boot\bcd /set GUID osdevice partition=C: bcdedit /store C:\boot\bcd /set GUID path \Windows\system32\winload.efi bcdedit /store C:\boot\bcd /displayorder GUID /addlast Older physical servers or VMs configured for legacy BIOS use MBR partitioning. Corruption here yields "Operating system not found."

bcdedit /export C:\bcd_backup attrib C:\boot\bcd -s -h -r ren C:\boot\bcd bcd.old bootrec /rebuildbcd