clintfan

I can't definitely explain that from here. It might help if in DeviceManager you switched the view to Devices by Connection instead of by Type. Then we could maybe see where the yellow-exclamation device falls out. Unfortunately VIA doesn't publish much detail about the internal stuff. But knowing what's above this device in the chain, may (or may not) give us a clue.

Your mobo has at least 2 different VIA controllers onboard. The 4in1 package gives you the VT8237 driver for the basic PATA ports PRI_IDE and SEC_IDE.

I'm having trouble remembering but FWIW I think there might be an embedded (aka. "OnChip") VT6420 chip inside the VT8237; this drives the SATA ports and uses a separate driver, VIA VT6420 (VT8237) SATA RAID Driver Package Version 2.20D WHQL. I think VIA didn't go with quite the homogeneous integrated scheme Intel uses, rather they use a chip-grouping scheme. In the end you need to load multiple drivers for different ports on the same chip.

The 6420 package has both PATA IDE driver and SATA driver components, since according to the Readme, the 6420 chip can apparently make a RAID with 2xSATA plus 2xPATA. But in your case I think only the SATA RAID applies, since Asus has only provides the SATA1 & 2 ports. When properly installed, I think that that RAID device should come up as "VIA Serial ATA RAID Controller". (I don't think the PRI_IDE & SEC_IDE ports can be used with RAID, I think they're driven some other way, bu the 4in1.)

I can't believe Windows would let you put the wrong driver on a device, and still be able to boot...? You said you put on every possible driver, but maybe somehow the driver for the RAID one never got on. Or maybe it refused to go on, perhaps because the Onchip SATA BOOTROM didn't get turned on in the BIOS? I'm not sure.

Hope something here helps,

-clintfan