I totally agree with Adrian about HDD. I have my internal HDD mounted on a drawer, and I have recently purchased a spare drawer (still in its box, not yet installed) for backup purpose or additional storage. As I have currently no available disk, I can't test but it would be very annoying if Octane would stop working when adding, changing or removing a disk.
Why not using as Computer ID only the network controler physical adress, like done by many software editor ? It is on the motherboard, and it is probably the thing that will never be changed except in extremely rare failure situation.
Is it not secure enough ?
When I ordered Octane, I spent a moment looking for it on my machine (I didn't remember the syntax of the command : ipconfig/all) before finding that you used an other method.