Disk read system question/problem

[CrazyWussian]

Hi, I just setup my first NAS build on a dell xenon 2.33 ghz dual core board with 4 gigs ram and what not. In my box there is room for 4 drives total, which are 1x500 GBs drive, 2x 250 GBs drive, and 1 x 160 BGs drives. I have on my mother board 3 Sata ports and 4 HDD ports that all take SATA cables. When i run this pc with a Win 7 Ulti, it shows 4 hard drives connected in any of the 7 ports, however, when i run FreeNas, it only seems to read the drives that are wired through the SATA ports. This makes me sad because i am loosing 160 GB of space do to a hardware deficiency. My question is; does FreeNas require the drives it uses to be wired through SATA ports on the motherboard? It seems like it does from trial and error, but i would appreciate some confirmation. Secondly, if that is the case, is there any way to enable the reading of the 4th drive if it is plugged in through a HDD port, or am i out of luck? Thanks