I have Windows 7 Home Premium 32bit installed on D2700DC. I've installed all "latest" drivers available on the product support & downloads page.
My problem is that the CPU is always at 2.13GHz and never gets throttled down. The CPU is always sitting at around 56C and memory hovers around 60C.
Windows doesn't show any options for "Processor power management" in my "Power saver" power plan - apart from "System cooling policy" which is set to "passive".
Now, I understand that SpeedStep is not available on this model. However, I also own a D525MW board which doesn't have SpeedStep, but is happily doing Dynamic Frequency Scaling under linux, with cpufreq. As a result D525MW CPU is at 29C.
With Atom processor, especially in a fanless design, it is essential to be able to throttle down CPU when idle. Not just does this save power (CPU+chipset+memory) but it also substantially reduces heat and drops the demand on cooling.
There are several utilities I have tried in order to throttle down the CPU. A while ago, I had success with CPUIdle and RMClock on Windows XP so it was worth having a go. All the utilities complain about ACPI not being usable, although I can see Microsoft's ACPI driver installed. I couldn't find an Intel ACPI driver, assuming there is one.