Not enough info. How about the make/model of drive and if it's sata or ide. Were you trying to boot off of it with a previous OS install? Anyhow, I'd try resetting the bios. Check your motherboard manual on how to do it or just pull the motherboard battery for a few minutes then put it back in.
i was not trying to boot from it, i have a ssd with the os on it and i just put a old hard drive in to see if it would work
this is it