: Writes a new boot sector onto the system partition.
If the Startup Repair tool fails to fix the issue, you can try running the Bootrec tool from the command prompt. Here are the steps: windows server 2012 r2 boot repair
Repairing the boot process for Windows Server 2012 R2 typically involves using the Windows Recovery Environment (WinRE) : Writes a new boot sector onto the system partition
bootrec /fixmbr bootrec /fixboot bootrec /scanos bootrec /rebuildbcd windows server 2012 r2 boot repair
(Ensure C: matches the actual drive letter where your Windows folder resides as viewed from WinRE). 2. Run System File Checker (SFC) Offline
Run this command to scan for Windows installations and add them to the BCD: bootrec /rebuildbcd Complete Manual BCD Rebuild
Recreate the BCD store by copying the essential boot files from your Windows directory to the EFI partition: bcdboot C:\Windows /s Z: /f UEFI (Assuming C: is your primary Windows installation drive). Phase 4: Using the Automatic Startup Repair Tool