I have a raid 5 setup with Windows 7 installed on it, I also have a secondary 400gb hard drive which I use for basic backups. It's all been working perfectly for the last year but yesterday I removed the 400gb to put in a 1TB drive and on boot I would get a message about inserting a disk to boot from DVD. As soon as I put the 400gb back in, everything is fine! Removing the 400gb and not attaching the 1TB returns the same result, it won't boot. It will only boot if that backup drive is attached to the system. I did delete everything from the backup drive (not format, just highlight/delete), so maybe it contains some kind of boot info that Windows 7 installed on it before it found my RAID and installed itself on that during the setup process, thus removing the backup drive means the boot info cannot be found? Does that make sense?? Any ideas? TIA.