I would like to give you a brief overview of what steps led me to this problem. My work requires me to encrypt a Windows drive with BitLocker that uses TPM. Originally, Linux Grub was installed on the MBR (sda1), so I could boot either in Linux or Windows from the Grub menu. However, BitLocker did not like this setup and refused to encrypt the Windows drive. To solve this problem without re-installing any system, I restored Windows MBR and installed grub on the same partition where the main Linux system resides (sda5). Then I copied the first 512 bytes of sda5 to a file which I put on sda1. Then I used bcdedit from the Windows repair disk to create a Linux entry in the Windows boot menu by pointing to this file.
It seemed that all went well, and Windows could boot without any problem, but when I try to boot into Ubuntu (12.04), I go directly to the grub console (i.e., 'GRUB>'). I tried different method to boot into Ubuntu from grub console, and all of them failed. I do not want to mess with the Windows MBR again as I read that BitLocker could refuse to decrypt the drive.
My question is how to fix this problem? Preferably by repairing the grub on the Linux partition? I know it is not a clear-cut issue as I must stick with Windows MBR to manage dual-boot. My main concern is if I try any grub repair programs, it could just overwrite Windows MBR with Linux boot loader. I will appreciate any advice and comments! Thank you in advance.