Nvidia display adapter disappeared

Hope someone can advise me on this one. Noticed my graphics in general and mouse movement in particular suddenly became very jerky. Tried to find my Nvidia control panel. No sign of it anywhere. Ran a Belarc system scan and it failed to detect any graphics software at all. Same with DirectX. I operate an Inspiron 1720 which came with a Nividia GeForce 8400M GS display adapter. My query is this: Can I reinstate Nividia without all the hassle of using the Symantics system restore. Is there a simpler way of getting Nvidia back in operation? Have downloaded the latest Nvidia drivers but of course they need a display adapter for installation. Very grateful for any advice.