Vista - Serious problm with directx in vista

HI guys, i have a problm with directx that i can't solve.I want to play COd4 but directdraw , direct3d and agp accelaration are disabled. I tried dxdiag tool but i cant enable them . The thing is that in Xp there is a button to enable them but there are no buttons to enble them in vista.
Can someone help me?
sorry for my bad english...im not english
system configuration:´
ram: 3gb
intel(r)pentium(r) dual cpu t2410 @2.00Ghz 2.00Ghz
os:32 bits
windows visa home premium
graphic card: SIs672 series 256mbs
-ticaw

Ticaw, if you don't post your System Specs, it will be hard for anybody to help you since, for starters, we don't know if your video card is a DX9 only or DX9/DX10 card, etc, etc, etc.

DOne

Im sure you've probably already done/checked these things but just incase. It never hurts to try the most obvious solutions first. I am not familiar with Sis brand video cards but I'm assuming just as ATI/Nvidia they have drivers and new ones relatively often so make sure you're running whatever the most recent version drivers for your version of Vista are. Preferably ones that WHQL Certified if SIS offers that. Also make sure you have the most recent release of DirectX as I believe there was a revision released just this month. I could be wrong but I'll see if I can confirm that and find you a link to download it. I'm assuming a simple google of Microsoft DirectX 10 would bring you to the appropriate place if not just simply running the Windows Update feature. Once you confirm you have done these two steps which I would consider the highest of priority if you have not done so as of yet, then we can begin with further troubleshooting.

EDIT: Here is a link to the Microsoft DirectX 10 Page if you have not downloaded the most recent version.
Download details: DirectX End-User Runtime

Don't know much about Laptops really but I think your CPU and video card are marginal for newer games... read something about the card here:

Sis Mirage 3 Video Card - Tech Support Guy Forums

All newer games require shader 2 or greater and I believe your card does not have this.

New video card is a definite, get an ATI or nVidia, all the other brands are garbage.