I'm planning on building a new core 2 duo based system with VIsta, and i noticed that its clock speed is only 1.86 ghz, i no this is really fast but, i'm wondering that will it score lower than my Pentium D 945 (3.4 ghz) on WinSat
No. Since it is a Core 2 Duo, which has 2 cores instead of 1, it will not score lower. It should score much higher.
The reason being is that the processing is shared by the dual cores instead of the 1 core having to do all the work. That way twice as much will be able to be processed in the same amount of time.
Yes a OC'd CPU would score better than stock on the Windows Index. But just beware of the heat the a OC'd CPU gives off. Dont want to burn it out before it is time.
I think it would be because of his RAM or CPU. The overall index score takes the lowest score. Not just that of certain parts you would have to look at the whole index to see which actually scored better or worse.
So click that link thing that says "What do these scores mean to me?" and see if his 8800GTX is still scored lower. If so then he needs to run the update since he changed hardware recently and it isnt reflecting the new change.