I don't doubt your sincerity, Lsdmeasap, or your expertise, but I don't think that anything you've suggested is likely to improve the situation I have. That's because if you read the details given by Intel about the INF file installed by infinst_autol.exe, you find that the INF file is a text file, and that only. Well, after all, that's primarily what an INF file's meant to be! Indeed, Intel seem to go out of their way to point out that it's only a text file. Therefore, installing a more up-to-date INF file, in this case, is, I think, very unlikely to make any functional difference to the chipset. Just to confuse things, though, my motherboard user manual has a page toward the back where it describes how to install the motherboard drivers from the CD that comes with the board- incidentally, something I'd never dream of doing, as the drivers would inevitably all be out-of-date - and, in that, you can clearly see that the INF driver is not just a text file but also includes USB drivers and a PCIe driver.
I don't know why you're suggesting I switch to AHCI. It's of no use to me, as I use just a single drive and in IDE mode. I've no intention of running two drives at once or doing any hot-swapping or anything like that. I'm not using Vista (perish the thought) or 7, anyway. I appreciate all you've posted about setting up AHCI but, really, I've no intention of using it.
As for the FDD issues, if you care to read my opening submission for this topic, all will be explained. From time to time, I get completely random accesses to the FDD happening. The FDD motor whirrs momentarily. (And no, I'm not clicking on the FDD at the time!). On average, about six per hour. Long ago, I swapped both the FDD and its cable for others but it still occurred. There's nothing in the FDD at the time. The FDD otherwise works fine; have used it for making various bootdisks. I strongly suspect that the random FDD accesses and the constant and very regular accesses to the hard drive are all part of the same bug. Never experienced it on any previous PC I've built, even one with the same operating system, apps and utilities. It's either a hardware problem of some sort, or (more likely) a badly-written BIOS or a faulty chipset driver. On the board, accesses to and from the floppy are controlled by the IT8720 chip. The COM port hanging off that chip works fine, as does the PS2 keyboard but I've noticed that the FDD random accesses often coincide with clicking of the USB-connected mouse, so I suspect that something's amiss with the operation of the IT8720, or the LPC bus.