D3D device?

just a few days ago i tryed to get on garrys mod
it wouldnt go on for some reason
an error popped up saying it failed to create the D3D device
what does this mean

Do you have the latest version of DirectX?

I dont think so
where do i get it

Do you know your graphics card? Can it play other source games well?

I had this, but I can’t remember what I did to fix it. Try following their link.

Does Direct3D work?

well it plays them for a short while then goes off
showing the graphics card message