Graphics card problem, no aero theme

hi i have agp graphics that stopped workng a while back, for some reason the aero theme stopped working and the pc i have i reinstalled windows 7 because of lag but when i did the agp wont be recognized by the pc and it shows vga adapter instead, i dont know whats wrong with it, yes i downloaded the software too but nothing

hi,

how the graphics card stopped working?

Please post your pc specification, especially your motherboard and graphics card model.
Some AGP cards with some motherboards are incopatible with Aero and WDDM drivers.