Hardware Monitor

Hardware Monitor is a lightweight system information tool that can monitor the essential hardware components under the hood of your computer and provide plenty of details.
Clearly aimed at those with a bit more computer knowledge, Hardware Monitor is otherwise a very easy to use piece of software, mostly thanks to its very straightforward approach.
There are settings to play with, that's true, but all the displayed information is packed into a single window and if you're okay with the standard options, you have almost nothing to change.
The main window shows you voltages, chassis fan, CPU fan and top chassis fan, MB, CPU and HDD temperature.
The configuration screen gives you the power to change fan and temperature names, but also to set up alarms and logging, as well as update interval to automatically refresh the displayed values at a user-defined interval.
On the good side, Hardware Monitor runs on very low resources and doesn't hamper system performance, despite the fact that it's supposed to run all the time and thus provide a better overview over the hardware side of your system.
On the other hand, Hardware Monitor fails to launch on Windows 7 workstations and doesn't support all hardware devices, which means that it can work only with a limited number of motherboards.
All things considered, Hardware Monitor is a helpful program in case you're one of the lucky users who own a compatible motherboard. There's no help file available, so make sure you know a thing or two about CPUs and voltages before launching this app.