I've got an Nvidia 7600GT in my PC at the moment but I think it's on its last legs as the PC keeps falling over with blank screens, then has garbage behind the boot screen when it restarts. I use the PC for the usual office stuff plus some CAD (including 3D) but not gaming or anything.

Any suggestions what a suitable replacement may be?

Thanks in advance

EDIT – forgot to say that an OpenGL compliant card is needed, whatever that is!