Boot Manager error

I bought a new HP laptop that came with just one partition having Windows Vista Ultimate 64bit. Yesterday I went to disk management and create Two more partitions by shrinking the only partition available. I made all these three partitions as primary partitions and now they are with Windows Vista, Windows XP and third partition with Data and files.

Today I used Acronis Disk Director Suite 10 and set XP partition as Active and hidden the VISTA partition. Later restarted the system and installed WinXP pro SP2 on the 2nd partition. Everything was working fine so far. Just an hour ago wheni tried to reverse the situation by hiding the XP partition and setting Vista back to Avitve, I got the following error message:

“Windows Boot Manager - Windows failed to start... File: \Boot\BCD Status: 0xc000000d Info: The windows Boot Configuration Data file is missing required information.”

As I don’t have any Vista Media Disk with me, can anyone please tell me how can I get back Vista working again? Many thanks.

You can install the OSs in any order using NT series 4.0 thru 2003-R2 and then copy the newest versions boot files (ntldr, ntdetect) to the root of the c: drive. Later then manually modify boot.ini to get all the OS paths right, and it would all work. This is because the modifications to the mbr and the partition boot sector continued the reference the same files, so only the content of the files mattered.

Also when you have Windows Vista already installed on the system and when you install an earlier version later in the installation sequence that creates problem because of mbr and boot sectors on C: no longer refer to the correct files. When you try to run from the vista partition, Boot Manager needs to control the whole process. Boot manager rather than ntlldr and boot.ini needs to be invoked and it needs to be the file that offers you the alternative OSs. However when your *original* partition is active the mbr is referring to the boot partition are on the second drive, that is looking for Boot Manager but finding ntldr.