I have built this machine which is my HTPC as well holding all my data. I leave it on almost 24/7 so im looking to make it use less power. I have 8GB ram and 3 hard drives in it. I dont need much power, just enough for boxee or xbmc no gaming at all really.

The bios has a bunch of options but i guess due to the chipset i cannot use them. I can use the ai suite II when i load windows to lower the voltage but after each restart it resets the settings so its not permanent as if it was in the bios.

There should be a way to make the voltage settings stick but with modern CPUs lowering the voltage is most useful when you're making the box work. It's an HTPC so I guess it mostly idle which means you wouldn't get large benefits from undervolting.

Perhaps you can underclock stuff in the BIOS since you probably only have a use for a fraction of the performance of your rig. You should at least be able to underclock the CPU but if you can underclock the board and the RAM it would make more difference.

The best thing you could do to lower power usage is to remove some RAM and to spin down the drives.
The way to spin down the drives depends on the OS but in general, you want them to spin down after they've been idle a while and you don't want to have to write logs to a hard drive and so forth. So you're talking about using Flash or RAM for this stuff.

Something else you can do is to set your HTPC to go into standby (suspend to RAM) when it's been idle for a while (maybe only at night and whenever you rarely use it anyway). Waking up from standby is very fast and can be done over the network rather than by pressing a button if you want.

You could also make sure you don't have software making the drives or the CPU work pointlessly like unneeded services, "anti-virus" software and whatnot.