Windows 8 will only boot with one Drive HELP NEEDED

I have a 'slight' dilemma when I have more than one hard drive that it wont boot and it when I try to boot with more than it will come up the error code that is saying that ' you have no boot files on that drive or something like that'. I have tried disconnecting the cable boot up the pc and connect the cable to no avail.

When you first start up your computer you have to go into BIOS and look for something called "boot priority" (or something similar to that) and you wanna choose the hard drive/SSD that you have your operating system on as number 1 priority.

That should do it!

still wont boot tried that already

Don't mind me while I fumble this. But in the BIOS, is there something about legacy or UEFI? That could be a cause...?

You could also look at what SATA controller the boot drive is connected to, dunno if that has anything to do with it.

Oh, and try to see which HDD is causing it, and see if there is a specific HDD causing the problems.

Sorry if this is a necrobump but I think I have may found the problem which is that during the installation of Windows, Windows will put other files onto other hard drives during the install and then when try to boot it will boot off the other hard drive not the one with the Windows on it. HELP NEEDED CAUSE I GOT STUFF THERE THAT I NEED DOING.

Listen, disconnect all drives except the one the OS will go on. Install windows to that drive. Then connect all other drives. This will work.

Tried doing that and still wont boot

Backup data, wipe everything, install OS to single drive, plug in the rest, then move you data. My guess is that something on the other drives is messing with windows.

I ended up formatting the HDD and it booted up fine...... there goes all my stuff on that drive.