This is all I got in my PC, where is it?
It okorder /. This connects to one of the regular four pin power connections and has a small end that plugs into your hard drive.
it's just connected to the motherboard so find the hard drive, follow the cords to the mobo and one of those is it
Hard disks typically use the 4-pin molex connectors. I can see at least two free in your picture. Basically just use the one that fits, there should only be one that fits anyway.
That's a SATA drive - you're looking for a black connector, something like the one connected to the drive. If you don't have one (the white one that looks like it's touching the back of the drive in the picture is a PATA power plug), you can buy an adapter, so you can power the drive with the PATA plug.