exactly which games is it letting you play? because Direct3D is the graphics API of DirectX. you'd have to be playing OpenGL-based games or something else to be able to play without Direct3D or DirectX.
try this
http://www.microsoft.com/download/en/details.aspx?id=35
also try using Windows Update to install available service pack(s).
there are a couple of problems i spotted in your DxDiag:
under your graphics card:
DDI Version: unknown
Video Accel:
Deinterlace Caps: n/a
D3D9 Overlay: n/a
DXVA-HD: n/a
DDraw Status: Not Available
D3D Status: Not Available
AGP Status: Not Available
that should not be like that.
it seems like your card isn't taking to DirectX, or vice versa.
could be a faulty Windows installation. try what i suggested above.