Unable to boot Windows 7 "error while reading boot configuration data" and inability to restore

Question

I have tried to install Windows 8 Pro over Windows 7 Ultimate, but the installation failed to install the new OS and even to restore the old one.

I get the following error:

File: \EFI\Microsoft\Boot\BCD
Description: an error occurred while attempting to read the boot configuration data

System setup

• Laptop is an ASUS N76VZ
• HDD0 (1TB): openSUSE 12.3 in EFI boot mode
• HDD1 (1TB): Windows 7 in EFI boot mode
• BitLocker suspended on C:\ before trying to install Win8
• Other partitions are TrueCrypt protected

Data is almost back up. I won't lose much by formatting, apart from hours of software reinstallation

Steps to create the problem

As I said, I tried to install Windows 8 pro upgrading the existing Windows 7 Ultimate. I started setup from Windows, suspended BitLocker as requested, uninstalled a few Intel USB 3.0 drivers that are not compatible with Windows 8 and let setup go.

When rebooted, it first started with the new Windows logo, then rebooted, as expected, an then the Windows Boot Manager screen appeared. Three menu options available:

• Windows 8
• Windows installation
• Windows 7

I tried to boot 8 for the first time, but it rebooted shortly after. Then I chose Windows installation and that time the Windows installer told me there was an error during the installation. OK, no problem, I can try again...

But now I can't boot Windows 7 anymore.

What I have tried

I found this article

I tried to boot from Win7 DVD (using UEFI) and use automatic system restore option. These failed (method 1 of linked article). I tried to open console and use bootrec /rebuildbcd. It detected D:\Windows as installation directory but the (translated into English) error is the following when I press [Y]es

Unable to identitfy the requested system device. More devices correspond to the identification criteria without distinction.

I guess that this refers to the Linux installation.

I would like to ask how to repair EFI boot partition for Windows 7 given that BitLocker is suspended

The question

How to fix that?

Answer 1

Self fixed. Here is how.

The short answer

Physically disconnect any other disk rather than Windows's boot drive, launch Recovery mode from DVD (booting with UEFI) and let Windows repair itelf

The explanation

Basically Windows Boot Repair doesn't like other UEFI-based OSes installed. I'll update the answer if disconnecting first hard drive helps me install Windows 8