Hopefully, once the IDE drive is formatted and no longer contains an OS, the BIOS will continue looking for one until it reaches the SATA drive.
Or it will be like my system and halts when Bios hits the first hard drive. That however is just a simple Bios boot order change and in a case like yours, it should be a one time thing.
Not confused at all, makes perfect sense. I think Western Digital has a HD copy utility somewhere that can transfer the OS from one WD HD to another. Since both my drives are WD, I assume it would update the MBR as well. Will see what happens.
Yes all major hard drive manufactures have this type of utility and that should work. Good luck.