If you have on board graphics -Intel 8 series & 9 series, and the older Via on board graphics, it willnot run
The latest "extreme" chips Intel 945 on PCI-e will run it, but older on board graphics will not, you would need to fit a graphics card if you PC will take one
However please post your Dxdiag, and we can check the above for you
(Start Button - click - select run - type Dxdiag - hit enter - select "save all information" - post using the 'go advanced' button at the bottom of the page of the new post - scroll down you'll see it)
Regards
Zy