A RAID controller might be a problem because almost every manufacturer does something different with the implementation. For that reason, it's usually the manufacturer that supplies those drivers, and with an older motherboard, you take your chances whether they'll update it for Win 7, or not.
Just so that I understand, I should ask... You can see the SATA drive in Device Manager? Are you able to see the drive under Administrative tools >> Storage? You would need to use Admin tools to initialize the drive (partition, format). You won't be able to see the drive in Explorer until it's been initialized and been given a drive letter.
Are you trying to use the SATA ports for a RAID array? If you are, your motherboard may not support Win 7 for RAID, and there isn't a lot you can do about that, unless Gigabyte decides to make a RAID driver for it. Even if it can't support RAID, Windows should still support the SATA interfaces in IDE mode on the board without a driver from Gigabyte.
@stormy13. Just saw your post after I wrote this. Excellent. I didn't think VIA was doing anything with the older stuff anymore. They've been concentrating on the small, low power EPIA line for the past while, and I thought they'd pretty much ended support for everything else. I'm sure I can use something in that link to fix something frustrating at work. Thanks!