That should be more than enough to run the game.
Do you have 2 different computers, or are you getting system information from 2 different places? The second amount of RAM seems more reasonable (512 + 256 MB), but I'm not sure about the 2 video cards.
When you run the configuration program test, what kind of frame rates are reported?
Are you shutting down all non-essential programs (especially anti-virus) before starting the game?
Have you checked Windows update site for Windows or driver updates?
Troubleshooting Tips (& manual install procedure)