OK, I've been having a bit of a play around with this again this morning, as it's something I'd love to have working, and I've not tried it for about a year.
As I said previously, for whatever reason, this used to work with XP on this same machine, but has never worked on Vista.
First, I just tried sleep mode again.
It shut down the power, and then immediately started back up again.
I restarted windows, visited the BIOS, and manually set to S3, out of these options.
Back to Vista, tried sleep, same thing happened.
So, I figured I'd try hibernate mode. Better than nothing.
I'd disabled this ages ago, so popped back to the command prompt, and enabled it using the powercfg /hibernate on command.
Tried Hibernate.
The system closed down, except for the fans.
The chassis fans, and the CPU fan were still spinning.
I also couldn't wake it up. I had to press the power button to wake it up again, at which point it went through the post again, and windows complained that it hadn't shut down properly. I rebooted windows, and disabled hibernate mode again.
I've looked at the advanced power options, and everything seems to be set to power savings mode.
When I first tried setting it up in Vista mine would shut down only the display, everything else including HDDs would stay on. It turned out that I had enabled 'high availablility away mode'. Make sure this is disabled (it's under the 'multimedia' options in the advanced power settings list).
I don't seem to have "high availability away mode" but I do have it set to the following.
I just had a look through the device manager, at human interface devices, and the allow device to wake computer is disabled on all those that have the option.
So I'm pretty stumped.
Back to having to use full shut down and reboot.
It's a shame, I'd love to use sleep mode sometimes, but for whatever reason, I just can't get it to work.
The Mobo I'm using is an Asus P5B, with the latest (2001) BIOS.
Vin.
EDIT: Anybody tried this?
http://slicksolutions.eu/mst.shtml
I may give it a download and try it later.
EDIT2: Didn't work for me. Selected sleep mode, it said it configured the system, tried it, and it started immediately after going to sleep again.