Make sure that the display card meets the minimum requirements for OpenGL support.
For OpenGL to operate in After Effects , the display card must use OpenGL 1.5 or later and have a minimum of 64 MB installed video RAM (VRAM).
To get the full benefit from OpenGL in After Effects, your card must use OpenGL 2.0 or later, have Shader support, and support for NPOT (Non Power of Two) textures.
OpenGL support prior to OpenGL 1.1 on Mac OS X, and 1.3 on Windows, causes After Effects to disable OpenGL features.