Expanding a bit on ico's reply: you don't need a driver specifically for your gfx card. NVidia has what are called "unified drivers" which are common to a wide range of gfx cards in the same series.
In fact, the driver provided by the manufacturer of your gfx card is just a copy of NVidia's unified driver. The driver provided for download from the NVidia website is always the latest version and will be much newer (and faster) than the one that came with the card.
If you want to find out for yourself, go to
http://www.nvidia.com, then to the "Download drivers" page. You will be presented with the option to choose your GPU series (GeForce 6 series in your case) and your OS. This will lead you to the download page.