: bootrec /fixboot Writes a new boot sector to the system partition, which is useful if the boot sector was replaced by a non-standard one or is corrupted. 4. Rebuilding the Boot Configuration Data (BCD)
For newer servers using UEFI instead of Legacy BIOS, the boot files reside on a small FAT32 EFI partition.
The BCD contains the boot parameters for the OS. If it is corrupted, you will often see errors like 0xc000000f or 0xc0000034 . Basic BCD Rebuild windows server 2012 r2 boot repair
: bootrec /fixmbr Writes a new Windows-compatible MBR to the system partition without overwriting the existing partition table.
: Run diskpart , then list vol . Look for a small volume (usually ~100-300MB) formatted as FAT32 . Assign a Letter : sel vol assign letter=S: exit Use code with caution. : bootrec /fixboot Writes a new boot sector
Most boot repairs require you to access the recovery tools. If the server cannot boot to the OS, follow these steps:
bcdedit /export C:\BCD_Backup attrib c:\boot\bcd -h -r -s ren c:\boot\bcd bcd.old Use code with caution. : bootrec /rebuildbcd 5. Repairing UEFI/GPT Boot Issues The BCD contains the boot parameters for the OS
: On the "Install Windows" screen, select your language and keyboard settings, then click Next .
The system will scan for issues like missing system files or corrupted boot configurations and attempt to fix them automatically. 3. Repairing the Boot Record (MBR & Boot Sector)
Sometimes a server gets stuck in a "Pending Updates" loop. You can often break this by renaming the pending XML file: