Mount And Blade Performance Why Is My Game Lagging?

Why is my game lagging? - mount and blade performance

Why the delay of the game. Mount & Blade Game Name
System
OS: Windows 2000/XP/Vista
Memory: 512 MB RAM
Graphics: Graphics card with at least 64MB of memory
Processor: 1.0 GHz
Hard Disk: 700 MB free hard disk space.

And my computer.
Processor speed: 2.31 GHz to 6.60 GHz nominal benefits
RAM You Have: 2.9 GB
Operating System: You Have: Microsoft Windows XP Professional (Build Service Pack 32600)
Video Card: You Have: NVIDIA GeForce 6150SE nForce 430 (GeForce 6150SE nForce 430)

Why is it delayed. I think my computer is fast enough.