Hi Godatum,
You should give your system specifications, without them we\'re unable to help you any further. How much memory, which OS and so on, like asked in the sticky threads on this forum.
You need OpenGL, yes. Don\'t try the software mode, you will be very disappointed and it doesn\'t do justice to the game\'s graphics. I would advise you to check on the nvidia site for up-to-date drivers :
http://www.nvidia.com.About your system : be sure to have enough memory, this program can eat up to 300 MB of memory, maybe more. If you don\'t have that much, be sure the virtual memory is large enough. Rely on the help of your OS for that part.
Good luck !