I have a new SATA 1 TB Seagate Barracuda, ST31000333AS. Currently I have Windows XP Pro SP3, AMD Sempron 2800+, 1GB RAM, and an ASUS A7V880 mobo BIOS version 08.00.09. Currently I am running off of a 120GB WD Caviar IDE drive. The BIOS and Windows won't detect the new 1TB SATA drive. I want the SATA drive to be a secondary drive.
In it the only reference I could find is on page 2-18. Under the headings of 2.4.2 Chipset ... Southbridge .. Configuration I see an item for enabling or disabling the VIA SATA Bootrom. This MIGHT be what you need, but be careful - it also can get you into using some of your drives in a RAID array, which you don't want. Do not create a RAID array or assign any drives to be used that way unless you actually want to. If this particular setting forces you into RAID use, then disable it.
I started with the BIOS settings because you say the BIOS does not recognize your new SATA drive. But there's another item you might need. Windows does not have drivers built in for SATA HDD's and they need to be installed. Some newer boards avoid this by having the BIOS take direct control of the SATA ports and making the drives appear to Windows to be simple IDE drives that it can handle. But if your mobo does not do that and only offers to use them as plain SATA drives, look on the CD that came with the mobo for driver installs, and see if it offers to install one for SATA drive use. Again, NOT one for RAID use of your drive if you have a choice of drivers. If you're going to continue to boot Windows from the IDE drive and use the SATA unit as a second data disk, this would all work just fine because Windows will be able to find and load its SATA device driver from the C: boot disk, and all is happy!