Argus Monitor is an interesting system information tool that enables you to keep an eye on your system temperature, fan speeds, hard drive status and many other vital system details.
The program is very easy to use. Once installed, launch it, and immediately you should see graphs of your CPU, GPU and hard drive temperatures. And a simple tabbed interface allows you to focus on any one of these attributes, making it easy to (for instance) see if your CPU is overheating when it runs processor-intensive apps.
An "HD S.M.A.R.T." tab additionally reports on details like spin up time, power cycles, host writes and more (if your hard drive is S.M.A.R.T.-compatible), though not as clearly or completely as we'd like.
A graph of your CPU core frequency lets you see if your power management plan is working properly. There are some useful system information screens. And if you find your system is overheating at any time, then the Fan Speed tab allows you to take control over your system and GPU fan speeds, ramping them up until your PC temperatures are back under control.
Argus Monitor does a reasonable job of tracking your system temperatures. It doesn't display all the available S.M.A.R.T. data, though, and probably isn't quite good enough to justify its price