CPU-Z

A small download that doesn't require installation, CPU-Z shows the candid specifics of your core hardware, including CPU, motherboard and RAM. Please be aware that some aspects of CPU-Z are orientated towards the expert, so certain types of information about your hardware is reported as real values and not marketing values.

For example, the FSB of a Pentium 4 3.2 GHz will appear as 200 MHz and not 800 MHz. This is because the 800 figure is arrived by multiplying the Front Side Bus frequency by the number of transfers per clock (4), to arrive at the Bus Speed. Other affected specifications are CPU cache, memory frequency and graphics interface.

If you have any concerns about your hardware specifications, post on the relevant forum board before jumping to conclusions.

PC Wizard

PC Wizard is a more comprehensive utility that covers many more aspects of the hardware and is aimed at a wider audience. A few benchmarking options are also available.

SiSoft Sandra

A mature suite, SiSoft Sandra is the most complete piece of hardware information and benchmarking software that I know of. There is a free "Lite" version that excludes mobile platform benchmarking and a number of information modules, but the full suite is licensed.