All was working OK on my last computer (a single core PC with Windows XP 32bit, 2Gb ram, and a GeForce 6600 graphics card) I have recently bought a new computer with an Intel core2 Quad Q9300 @ 2.5Ghz, 4Gb DDR2 ram, Asus P5N-D motherboard with a ATI Radeon HD 3800 series graphics card installed. The operating system is Vista Home Premium 64bit. Terragen 2 (latest and older builds) installed OK, but when I try to run the program it ceases to run after telling me it has recognised 4 cores. Windows message begins "A problem caused the program to stop working properly. Windows will close the program . . . . ". I have installed the latest drivers for the graphics card but this makes no difference. I have exactly the same problem with Blender. World Machine 2 starts but the user interface is faulty, and stops working as soon as I go to Explorer view. Vue 6 Esprit opens with a warning that my graphics card is not recognised properly and advises me to go to compatibility mode which then switches to using OpenGL software instead of OpenGL hardware acceleration. I suspect that I need to change my graphics card. Can you advise me which cards will successfully run Terragen 2 and work with Vista 64bit operating system.