Even though this board might be old here is the solution I ran into:

My Setup:

Intel Pentium D 3.20GHz

2Gb RAM

NVidia Quadro FX580 512MB GDDR3

Windows XP Pro SP3

I was running into the same issue with the slow down when you saw others field of vision. Since my motherboard has onboard video I took out my NVidia Graphic Card and used the onboard and started the game and everything works great. Don't know why the video card was a problem. Tried putting back in the NVidia card and mess with the settings, but still would go slow. I can only run the game without any problems by using the on board video. Hope this solution works for others.