When you do Ctrl-Alt-F2 you should be switched to a console and see a # prompt, do this command:
And you should see some directories listed, including /var. That way you know you are in fact in a console. Then the commands should work.
In your posts you have made reference to both an install CD and DVD. I presume it is the DVD. I haven't tested the above using the CD, only the DVD.
What you found re the MS requirement and AHCI is not surprising, and is somewhat analagous to Linux. I'm surprised you have to reinstall Vista to make the change though; can't you use the Vista Recovery Environment command line shell to change the Registry?
I looked at the thread at nvnews and I think it fair to conclude you are looking in the right area - bios setting vis-a-vis disk controller vis-a-v-is the kernel, specific to the 750a chipset - but given that that user had a RAID setup, we can't directly extrapolate to your situation. Once you set your bios to AHCI, and working off the theory that the linux kernel needs to use the ahci driver instead of sata_nv, then when you look at the kernel log check which driver the kernel is loading. If it is sata_nv and not ahci, you can try this: On the DVD menu below there is a place to type Boot Options, type this:
That may force the kernel to use the ahci driver. If you are seeing a timeout error - the kernel will say it is trying to detect on a channel and getting slow response, eventually it gives up - then swap the SATA drive cables on the ports. There are known issues with some controllers having the quirk, with a given drive cabling setup, of being slow to respond and timing out. If you see this, you can also try installing from 11.1 RC1 with its newer kernel.