In order for you to play Jamestown on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Microsoft® Windows® XP with SP2 / Vista / 7
Processor (CPU):
Intel® Pentium™ 4 2.4 GHz or better
Memory (RAM):
512 MB RAM
Hard Disk Space:
250 MB
Video Card:
Any OpenGL 2.0 graphics card with 256MB+ video RAM and full GLSL support
DirectX®:
DirectX® 9.0c
Additional:
One keyboard, controller, or mouse required per player. Supports multiple mice and/or keyboards. 3-buttons required for mouse play.