Yes I agree Dxdiag is also very useful.
I think Win7 shows far more information than previous versions. When I had Win98 I couldn't find a thing about my PC and then found SiSoft Sandra which gave me too much information (....better having then have not right?).
I only posted this after reading questions like is my graphics card AGP or PCI or on-board or DVI or Dsub and how much memory can my PC take etc etc. Sisoft opens your eyes wide.
Doesn't replace the wealth of information on this forum though