winXP SP3 doesn't see sata ii hdd

I had a similar problem a week ago in that the ...\DEFAULT file was
corrupted. It was fixed and all was well. This time there is no indication
of the problem except that it doesn't recognize the SATA II 500 GB WD hdd.
The HDD is fixed with a controller card that has Sil Graphics drivers for it.
The mobo is ASUS A7V8X which is 6-weeks newly installed (I had it sitting in
it's shipping box since 2003).

The WinXP install CD has the drivers integrated into it and it has worked
well previously. The BIOS recognizes the HDD. Fortunately, there is a
second 40 GB IDE HDD that is used as a backup drive for the SATA drive. The
SATA drive is not recognized anywhere in the Windows environment. I hate to
have to reformat the darn thing as there is about 38GB of backup to replace.
It seems like there should be a way to get it to be recognized, but I sure
can't figure it out.