Speccy will give you detailed statistics on every piece of hardware in your computer. Including CPU, Motherboard, RAM, Graphics Cards, Hard Disks, Optical Drives, Audio support. Additionally Speccy adds the temperatures of your different components, so you can easily see if there's a problem.
Some of the basic information can be found by right-clicking My Computer and then clicking Properties. The General tab lists some statistics, and the Device Manager on the Hardware tab lists all of the hardware you've got installed. But it misses out lots of information that you need.