SATA HDD not showing up

I just installed a new power supply (700w OCZ, 100w more than my previous one xD), and after hooking everything up, I noticed my SATA hard drive isn't showing up (my other 2 IDE ones are). The power is all hooked up and so is the sata cable. I also have a sata dvd drive that's hooked up to the same line as the hard drive is, and the dvd drive works. I'm not sure but I also think my BIOS detects the hard drive, but it just doesn't show up when I start up windows. Would anyone know what the problem with this is?

basic rule of setting up devices on sata:

first hdd
2nd dvd

if you buy another and you do this

first hdd
2nd dvd
3rd hdd

the 3rd wont show up

so you need to put it like this:

first hdd
2nd hdd
3rd dvd

no matter how you put it: hdds first then dvds