Windows Server 2012 R2 Boot Repair [upd]

Repairing a Windows Server 2012 R2 boot failure typically involves using the Windows Recovery Environment (WinRE) to rebuild the Boot Configuration Data (BCD) or fix the Master Boot Record (MBR). 1. Access the Recovery Environment

Boot from installation media and open Command Prompt from Advanced Options.
Identify the system partition. Type:
```
diskpart
list disk
select disk 0   (adjust to your boot disk)
list volume
exit
```
Look for a small partition (≈100 MB for UEFI, ≈350 MB for BIOS) marked as "System" or "EFI". Note its drive letter (often D: or C:).

Verify boot files on the system partition:

dir D:\EFI\Microsoft\Boot   (for UEFI)
dir C:\Boot                 (for BIOS)

If files are missing or corrupted, rebuild the BCD:

bootrec /scanos
bootrec /fixmbr
bootrec /fixboot
bootrec /rebuildbcd

Rename the current hives (as backup):

The disk has physical damage (bad sectors increase over time).
You see repeated 0xc0000225, 0xc000000f, or 0xc0000001 after multiple repair attempts.
The server is part of a cluster or domain controller (rebuilding may be faster and safer).

Select that volume (sel vol X) and assign it a letter (assign letter=S). windows server 2012 r2 boot repair

Repairing the boot process for Windows Server 2012 R2 is a common task when a server fails to start after a power outage, update, or hardware change. Phase 1: Accessing the Recovery Environment To perform repairs, you must boot from the original Windows Server 2012 R2 installation media (USB or DVD). Boot from Media : Insert your media and boot the server. Language Settings : Select your language and keyboard layout, then click Repair Your Computer : Instead of "Install Now," click Repair your computer in the bottom-left corner. Choose Troubleshoot Troubleshoot Advanced options Command Prompt Repairing a Windows Server 2012 R2 boot failure

Hyper-V Gen1 to Gen2: Need to inject synthetic SCSI controller driver.
VMware to Hyper-V: Remove VMware Tools drivers offline via dism /image:D:\ /remove-driver before injecting Hyper-V integration services.