Yes, a G41 and latest drivers are supporting OpenGL 2.1, so it’s enough to work with Blender as it support every Blender features.
Previously i had a weaker “card”, a G31/33 that supported only OpenGL 1.4 and still Blender worked very well, only the GLSL features were not functionning (GLSL requiring more than OpenGL 1.5), and people have been using Blender with even weaker component, so don’t worry about your system, it’s good enough.
More memory is always good anyways.