Windows 7: NTLDR missing? Please HELP!

I woke up a few days ago to find my computer wouldn't turn on. To diagnose the problem I removed the motherboard from the chassis. I identfied the problem as a dead PSU (don't trust Hiper... I have now known several of these to break after a year).

Any way, I order a new PSU reassembled the computer and fired it up. After the initial BIOS post I got the error message 'BOOTMGR missing. Press ctrl+alt+del to restart'. Now I am guessing this is because I put the SATA cables from the HDD to different slots on the motherboard from which they originally came. I can access either my windows installs by loading the boot menu and selecting the HDD with my 7 install on so its not the end of the world. But my question is this: is there a quick fix to this (edit boot.ini?) or do I have to trial and error the correct SATA config?



I should mention I have 2 HDDs each with 2 partitions - 1 system partition and 1 storage partition on each. I have XP and 7 on the system partitions. (due to the crappy XP setup the storage partition on the XP disk comes at the start of the disk and the system partition at the end meaning that boot.ini and ntlfr are in the root of the storage not the system partition).

Would appreciate any help that people can offer on this!!