Computer Help.

[Lirange]

What would i need to upgrade to play this game without no lag.
My system.
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System Information
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Time of this report: 9/23/2009, 07:32:44
Machine name: HOME
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_rtm.040803-2158)
Language: English (Regional Setting: English)
System Manufacturer: Dell Inc.
System Model: Dell DXP051
BIOS: Phoenix ROM BIOS PLUS Version 1.10 A02
Processor: Intel(R) Pentium(R) D CPU 2.80GHz (2 CPUs)
Memory: 510MB RAM

The game's min and recommended system requirements.
Minimum:
Processor - 2.2GHz Pentium 4 / AMD 2400+ or faster
RAM - 1GB of RAM
Video Card - GeForce 5 and ATI 9800 w/ 128 MB VRAM
Windows XP, Win2k or Windows Vista
Network Connection Required
Recommended:
Processor - 2.0GHz Core 2 Duo / AMD 3500+ or faster
RAM - 1.5GB or higher
Video Card - 256MB Geforce 7800+ or Radeon X1900+
Network Connection Required (Broadband)