goto the download page :)
http://www.cpuid.com/softwares/cpu-z.html
there are several versions to download.
INSTALLER - this will install the program on your computer (which may be easier if you don't know what version your operating system is.
ZIP VERSIONS - these are zip files, you can unzip and then run with no installation.
It is important to note that for this you need to know if your operating system is 32 or 64 bit (if you have no idea use the installer :)
here is a screen shot of the download screen as of September 26 2011. With the download area highlighted.
STEP TWO :
Run the program. Either the installed or unzipped program. it will then collect information and open itself to look like the screen below.
You will notice a number of tabs at the top of the page, each tab has different information. And you will not necessarily need to use all the tabs.
--The first CPU tab will give you the processor name (as highlighted in a greenish rectangle - mine being and Intel Xeon 3040).
--The third MAINBOARD tab will give you details on your motherboard.
Again highlighted in a greenish rectangle mine is an ASUSTeK P5GC-MX/1333.
--The fourth MEMORY tab will give details about the RAM installed.
Here mine is DDR2, 2048 MBytes.
--The fifth GRAPHICS tab will give details of graphical devices installed.
The green rectangles are currently displaying the device selected, and memory details.
NVIDIA GeForce 9600 GT with 512 MBytes.
The red rectangle will allow you to choose between all devices installed if you have more than one. I have only one so this option is greyed out.
great :)