How to Repair the Boot Files in Windows Server 2012 R2 or 2012 R2 if the Server Won't Boot
Boot to the Windows Server DVD.
Open the command prompt.
Server 2012 R2 & 2016 R2:
If no driver is needed, press Shift-F10 to open the command prompt.
Continue with step 3.
Server 2008 (or 2008 R2 if a driver is required)
Click Next at the first screen.
lick Repair your computer.
If no driver is needed, click Next and proceed to step vii below.
If a driver is needed, click Load Drivers.
Insert the media containing the needed driver.
Note: The media can be a CD, DVD, or USB storage device
Navigate to the folder containing the driver, select it, and click Open.
Click Command Prompt.
The command prompt appears.
Type DiskPart at the command prompt.
I_Windows_Boot5_JP_V1a.jpg
Type List vol at the DiskPart prompt.
Write down the drive letter of the DVD drive. In this example, it is F.
Write down the drive letter of the system reserved drive. In this example, it is C.
Type Select vol 1 (assuming volume 1 is the System Reserved volume, as it is here).
Type active. This sets the selected volume as active.
Type exit to return to the command line.
Type Copy f:\BootMgr c:\ at the command prompt. One of two things will happen:
If the file Bootmgr already exists on C:, type N to avoid overwriting it. If the file Bootmgr doesn't already exist on C:, it will automatically be copied.
Type Bootrec /Fixmbr at the command prompt.
Type Bootrec /Fixboot at the command prompt.
Type Bootrec /rebuildBCD at the command prompt.
If no OS is found, the following appears:
I_Windows_Boot8_JP_V1a.jpg
This means that one of the following is true:
a. The boot configuration database (BCD) already exists.
b. The OS is not there.
c. The OS is damaged beyond the ability of BootRec to recognize it.
If BootRec /RebuildBCD succeeds, it will list any installations of Windows that it found. Press Y to accept and add them to the BCD.
The server is now configured to boot from the proper partition. Close the command prompt and reboot the system into normal mode.
