hard drive installation problems

hey
i just pulled a hard drive out of my other computer to try and put it on the one that i do use. heres the problem, i hooked it up and lugged it in, and when i turned on my computer it wouldnt turn on. it kept turning on for a brief second then turning off. what would you do in my situation. im trying to use it as storage, and extra space on my computer.

What happens exactly?...

If the fans dont cut on then the power supply might not be firmly plugged in either to the motherboard or the power cable.

If there are any beeps or boops when you boot up those can be interpreted as error messages.

Is there any thing that come on the screen if it does come up?

Most likely you knocked something lose when moving the drive so just reattach any cables, ram, cards, cpu. Those can stop a boot process if loose.