Csdrhrt

Apologies in advance if this has been previously discussed, I did my best attempt at searching and could not find what I was looking for.

My issue is that I have a windows 8 vhd I want to update to 8.1 and from what I understand the only way to do this is with a virtual box vm because windows will think its not a virtual drive and it will install (I also hope to be able to native boot the vhd again once updated to 8.1). When I try to boot the vhd in virtual machine I get the error "The boot configuration data file doesnt contain valid information for an operating system, error 0xc0000098. I have been trying to follow this suggestion: https://superuser.com/a/571912/317553 but I am stuck where it says to "Select the file "BCD" in the folder "BCD" and click "open". Take note that the file has no file ending." because I cant find any bcd file or folder. So my question is, is what is the simplest way to accomplish this, and more importantly is it possible ?

What I have tried so far:

"Use a tool to install a BCD-Bootsector to the drive. I used NeoSmart's EasyBCD: Start the tool and choose BCD Deployment. Under "Create Bootable External Media" choose the drive name of the mounted VHD and click on "Install BCD"." -from the answer in the provided link, and this produces the error I mentioned

Using a VM for updating would considerably slow the update process but it seems to be the only way
to update Win 8 VHD to Win 8.1. HYPER-V can run Windows 8 VHD so a second native installation of Windows 8 could serve as host for the update.

To make VHD bootable in VM use following steps:

A) Write a MBR and PBR record to VHD itself using bootsect:

(In Windows 8 using admin command prompt, assuming VHD is mapped to V:)

bootsect /nt60 v: /mbr

B) Using Disk Management ensure VHD single partition is marked as active, if not mark as active.

C) Create BCD inside VHD:

bcdboot v:windows /s v:

If you are booted in Windows 8 VHD itself then V: would become C: !

One last thing. A Windows VHD installation is a native installation - it uses all computer hardware plus the virtual disk layer. A VM is a different computer hardware so you have to activate Windows again eventually.

It seems you have problems with BCD.

I had the same problems when booting from Windows 7 VHD (created with VirtualBox).
This article from TechNet helped me too much (I will summarize it's content).

All you need to do is:

1. Attach that VHD using Diskpart (explained in that technet article) or use Disk Management
   
   (press Win+R, type diskmgmt.msc, hit Enter, choose Action menu -> Attach VHD).



2. 
   

   Add boot entry using BCDTool (here is text from article)

   
   
   

   
   

   Use the BCDboot tool, located in the System32 directory of the VHD
   image or in Windows PE to copy the boot environment files and Boot
   Configuration Data (BCD) configuration from the Windows directory in
   the VHD to the system partition. On a computer with BIOS firmware, the
   system partition is the active partition of the first hard disk. For
   example, to use BCDboot from the VHD image, at a command prompt, type:
   
   cd v:windowssystem32
   
   bcdboot v:windows

   
   

   
   
   

   In this step I used Windows 7 installation disk (Win 8 will work the same way), booted from disk, get to Recovery and run command line. Then I typed that last 2 commands.
   
   (There may be a lot of alternative ways of doing this step by using tools, WinPE disks and so on).

   
   



3. Restart the computer, choose the OS and run.

NOTE: If you have UEFI-based computer then this will not work. Look here again for instructions.

Hope it helps!