BCD and disc signatures

[wjansoone]

Hello,

I have Windows 2008 R2 installed on C:\. From within Windows 2008 R2 I installed Windows 7 RC on external sata drive (mounted as drive E from diskmanagement) . Dual boot works OK.

Then I disconnect first esata and connect a second one (identical, also drive E). I perform same steps as before to install Windows 7 RTM. Dual boot with this drive works OK.

Problem !!!

If I now connect to my first esata drive again, dual boot does not work anymore. I get :

Windows Failed to start. A recent hardware ...

I did some research and my guess is that it is the signature of the drive that plays havoc with the BCD.

So here are my questions:

- Is my guess OK
- If so how can I modify the drive signature within the BCD store since I do not see any reference in the BCD elements.

Thanks for your feedback.

Regards,

Wilke

 

[sup3rsprt]

hello, please post the output of bcdedit /enum ALL

Maybe you need to create another boot entry. So you end up with three

Windows Server 2008 R2
Windows 7 RC
Windows 7 RTM

 

[wjansoone]

Hello,

I eventually got it working. I forgot to mention that I deleted the BCD entry for the first Windows 7 installation, my mistake.

By looking a bit further I found that the BCD elements 11000001 and 21000001 (Device and OSDevice) contains the disk signature.
So I exported the BCD object for the working Windows 7 installation via regedit, I changed the disk signature and the Guid and then imported it back again. Then I needed to add the new entry in the bootmanager bcd object (BCD element 24000001, displayorder)
After this I coukd again use my two Windows 7 installations.

Wilke

 

[shriganeshs]

Hi Wilke,
I read your reply and regarding how you managed to fix BCD. I have a situation where I have virtual disk with Windows 2008 R2 Standard edition installed (its a guest OS on Xen). Its a bootable image and everything is working. Now I mount this image as data disk on another windows VM and somehow the disk signature gets modified. Now after un-mounting the image is not booting. The reason behind this is the disk signature of disk and disk signature stored in BCD does not match.
I want to fix this problem, but I don't have a Windows 2008 installation disk to repair the non-bootable image.
How can I read disk signature from BCD? OR How can I write disk signature in BCD? Remember I need to do this from another Windows VM by mounting this non-bootable image (as I don't have a repair CD/DVD/ISO).
Thank you in advance.
~Shri