How to manually update the Windows 8.1 Boot Files to fix Boot Issues
Boot Files Issues
Sometimes you may have to manually update the boot files to fix the boot file corruption or compatibility issue. For example, the https://support.microsoft.com/kb/2883200 requires https://support.microsoft.com/kb/2894179 to be installed first .
It's mentioned in the KB https://support.microsoft.com/kb/2883200
Prerequisites
To apply this update, you must be running Windows 8.1, Windows Server 2012 R2, or Windows RT 8.1.
Update 2894179 is a prerequisite of update 2883200 and update 2894029 on Intel Bay trail-based computers. Therefore, install update 2894179 before you install update 2883200 and update 2894029
If you manually update the hotfix 2894029, you may forget to update the 2894179. In that situation, your Windows 8.1 may freeze or just blue screen during boot. Or you find you are in the situation like https://support.microsoft.com/kb/2846298. However, if you update the hotfixes from Windows Update server, you don't need to worry about it. The Windows Update will take care of the prerequisites for you.
There are other situations, that may require you to fix the boot file issues manually.
How to fix
So the question here is how to fix it? Let's start with what the boot files are and where they are located.
There are two kinds of systems, the Legacy BIOS and UEFI. Different system requires different boot files. Now we use UEFI as sample
UEFI
====
On System (EFI) partition
EFI\Microsoft\Boot\Bootmgfw.efi
EFI\Microsoft\Boot\Bootmgr.efi
On Windows partition
C:\Windows\System32\winload.efi
C:\Windows\System32\winresume.efi
So here please find the demonstration how to update the boot files from 2894179 to the system.
1. Build a WINPE 5.1 bootable USB key
https://technet.microsoft.com/en-us/library/hh825110.aspx
2. Find the hotfix, download the hotfix and extract the files
Download KB2894179 from https://support.microsoft.com/kb/2883200
Extract the file:
expand -F:* <update.msu> C:<target_dir>
expand -F:* <update.cab> C:<target_dir>
3. Copy the extracted files to the USB key
bootmgfw.efi, bootmgr.efi, winload.efi, winresume.efi
4. Update the boot files (The UEFI and Legacy BIOS steps are similar)
a. boot to WINPE
b. use diskpart to identify the partition and assign the drive letter to System partition (EFI or Legacy BIOS)
https://support.microsoft.com/kb/300415
c1. In EFI system
Backup and then Copy the two boot files to the System Partition
Backup and then Copy the two win* files to the Windows\System32 folder
(c2. In Legacy BIOS, update the boot files manually.)
5. Use DISM to update the hotfix to the WINRE package, or you may do it later. WINRE is for recovery package, not for normal Windows boot.
DISM Command Reference: https://technet.microsoft.com/en-us/library/dd744311(v=WS.10).aspx
You are now able to boot to the Windows again! :)
6. Once Windows is bootable, Install the hotfix 2894179 so that all files are updated correctly.
Note:
1. You may update the system to the latest hotfix which is in the Windows 8.1 April 2014 Update.
https://support.microsoft.com/kb/2919355
2. For other commands that fix the boot related issues, please check
bcdboot: https://technet.microsoft.com/en-us/library/dd744347(v=ws.10).aspx
Bootsect: https://technet.microsoft.com/en-us/library/dd744577(v=ws.10).aspx
Expand: https://technet.microsoft.com/en-us/library/dd744339(v=ws.10).aspx
3. If the Windows drive is BitLocker enabled, or your disk controller requires additional driver, you may need to add the BitLocker support or add the device driver to the WINPE boot.