Can anyone recommend some good software for monitoring, the system, ie CPU/Motherboard temp etc. My case is beginning to feel a little warm and I am worried CPU might fail.

Instead of spending money for this, why not invest in a new or an additional fan for the case or the CPU? you should not have to monitor cpu. Some cpu's shut down when overheated...go to the cpu makers site and find out if yours can do this.

Mother Board Monitor is a good program, and free if I recall. Many newer motherboards have a temp, fan, ect monitoring program bundled with them. Thing to remember is that unless your motherboard supports monitoring I'm fairly sure you won't be able to monitor temps or fan speeds, ect, no matter what software you use.

Thanks all for the replies. My first system had an extra case fan, but my new replacement arrived without one. When I complained, Evesham told me my new system did not need a case fan as the power supply, CPU and graphics card had them installed. I think I will demand a new one. My Asus board came with PC Probe, but everything I have seen keeps saying not to use it as it gives false readings. Even my Pc manufacturer told me not to rely on it.

None of the hard ware monitoring programs are that accurate. They are more of a guide. As for the case fan, It doesn't matter how many fans are inside stirring up the air, if nothing is expeling that air! There is a bit of a science to getting the proper air flow through a case. Do a little research. Look for sites on overclocking and case moding. They are the most likely place to find good information about keeping your computers temp down. Try Mother Board Monitor, it gets good reviews. http://mbm.livewiredev.com/ Just keep in mind that the placement of your temp probes as well as if a fan is blowing on it can dramaticly increse inaccuracies. The optimal placement for a temp probe is inside the CPU core, hehe. The worst part is...you have no choice in how the probes are placed. It's all up to the CPU manufacturer if they want to include a temp diode, and the hardware manufacturer on placement of board probes.