Sometimes bootrec /rebuildbcd fails with "Element not found." Use BCDEdit:
Few IT scenarios induce as much immediate stress as a production server that refuses to start. When that server is running Windows Server 2012 R2—a workhorse operating system still powering countless domain controllers, file servers, and application hosts—boot failures can paralyze an entire organization.
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. windows server 2012 r2 boot repair
From Command Prompt:
Introduction: The Critical Nature of a Server That Won’t Boot Sometimes bootrec /rebuildbcd fails with "Element not found
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.
bcdedit /export C:\bcd_backup attrib C:\boot\bcd -s -h -r ren C:\boot\bcd bcd.old bootrec /rebuildbcd That last resort wipes configuration, roles, and data
Whether you are facing the ominous "INACCESSIBLE_BOOT_DEVICE" blue screen, a black screen with a blinking cursor, or the frustrating automatic repair loop, this guide provides a systematic, step-by-step methodology to diagnose and repair boot issues on Windows Server 2012 R2.