On every version of Windows starting from Vista, there is a built-in benchmarking program known as the "Windows Experience Index". What it does is rate various components of your system based on what it can do capability wise, from a 1.0 to 7.9 (and later 9.9).

What I've noticed are a few interesting behaviors. If you have less than 2 GB available, your RAM score will be penalized. This may not be a reflection on your memory performance because you could have the fastest stuff in the world, it would still be penalized.
Likewise, I have noticed that hard drives seem to always get up in the fives in terms of ratings. Even an old ATA-133 drive I had scored a 5.1!

And recently, I noticed that Windows 8 failed to run the DirectX 10 tests properly thus the system could not be rated.

Let's take a look at my setup: a T61 with a 2.4 GHz T7700 processor, four GB of RAM, a 320GB 5400.6 Seagate drive, and using the integrated Intel graphics.
The assessment could run fine on Windows 7, so why not Windows 8?

Perhaps Windows 8 pushes for more GPU power than is available on the integrated graphics, but I have no idea. Bottom line is, I had to hack together something that was semi-accurate.

I found this page, and with a little bit of hacking together I created a WinSAT XML file that worked with the WEI program.

But my question to Microsoft (if they will ever read this) is, why did the benchmark fail on Windows 8 where it previously worked (on the same hardware) in Windows 7?
That is what baffles me.