If you are running Windows 7, this is probably a CoCreate Modeling question rather than a Modeling Personal Edition question. Unless something has changed recently, CoCreate Modeling Personal Edition will not run on Windows 7. (search this forum) Sorry to hear that you purchased the system because of the G-Force graphics card. Nvidia G-Force cards are designed for gaming applications. Nvidia does not support this card for 3D CAD programs. Games usually use DirectX graphics, while CAD applications use Open-GL. For 3D CAD, Invidia markets the Quatro series graphics cards. Because Nvidia does not support 3D CAD applications with this card, CoCreate cannot support them either. They may work most of the time, but you can experience some strange behavior. Check your graphics driver settings. With some cards, you can turn hardware acceleration off. If you cannot do this, you can try setting a system variable that will turn it off for the CoCreate Modeling application. SDPIXELFORMAT=SOFTWARE Then, restart CoCreate Modeling and see if your problem goes away.