Why? New ones are not only very cheap but you know that they are going to work.
Has it been formatted? If so what format?
What operating system is on your computer?
How are you using it?
Is it a PC or a laptop?
Is your original HD still fitted?
Did you install it as a slave drive? Set the jumpers to slave?
It looks like you have tried to install it as a master HD and your computer is wanting to boot from it but cannot because it is not the OS that the motherboard recognises.
What did you intend using it has, a slave HD or in place of your original HD. Because if the latter, you are out of luck unless you have a system backup disk.