Computer locks up in Games

[TLAM Strike]

Occasionally my computer will lock up in games (its only happened in games, not in any 3d modeling software like max). Its happned in Europa Universalist III, Shells of Fury, Call of Duty I. Very low end games will not seem to lock it up like Harpoon I. Anyone have any ideas, below is a report on my rig.

--------[ EVEREST Home Edition (c) 2003-2005 Lavalys, Inc. ]------------------------------------------------------------

Version EVEREST v2.20.405
Homepage http://www.lavalys.com/
Report Type Quick Report
Computer UGM-109A-TLAM-N
Generator ************
Operating System Microsoft Windows XP Professional 5.1.2600 (WinXP Retail)
Date 2010-05-25
Time 22:25


--------[ Summary ]-----------------------------------------------------------------------------------------------------

Computer:
Operating System Microsoft Windows XP Professional
OS Service Pack Service Pack 2
DirectX 4.09.00.0904 (DirectX 9.0c)
Computer Name UGM-109A-TLAM-N
User Name ***************

Motherboard:
CPU Type Intel Celeron D 320, 2400 MHz (18 x 133)
Motherboard Name MSI P4MAM2-V (MS-7095) (3 PCI, 1 AGP, 1 CNR, 2 DDR DIMM, Audio, Video, LAN)
Motherboard Chipset VIA VT8751A Apollo P4M266A
System Memory 1024 MB (PC3200 DDR SDRAM)
BIOS Type Award (03/30/05)
Communication Port Communications Port (COM1)
Communication Port Communications Port (COM2)
Communication Port ECP Printer Port (LPT1)

Display:
Video Adapter GeForce 6200 (256 MB)
Video Adapter NVIDIA GeForce 6200 (256 MB)
3D Accelerator nVIDIA GeForce 6200 AGP
Monitor Dell M780 [17" CRT] (5322DE6CXF89)
Monitor NEC MultiSync FE700 [17" CRT] (0587953BA)

Multimedia:
Audio Adapter Creative SB Live! Value (CT4780) Sound Card
Audio Adapter VIA AC'97 Enhanced Audio Controller

Storage:
IDE Controller VIA Bus Master IDE Controller
SCSI/RAID Controller Virtual CloneDrive
Disk Drive WDC WD400BB-00FJA0 (37 GB, IDE)
Disk Drive WDC AC313500D (12 GB, IDE)
Optical Drive ELBY CLONEDRIVE SCSI CdRom Device (Virtual CD-ROM)
Optical Drive LG DVD-ROM DRD8160B (16x/48x DVD-ROM)
Optical Drive Optiarc DVD RW AD-7200A
SMART Hard Disks Status OK

Partitions:
C: (NTFS) 12935 MB (2351 MB free)
D: (NTFS) 38154 MB (2840 MB free)
Total Size 51089 MB (5191 MB free)

Input:
Keyboard Standard 101/102-Key or Microsoft Natural PS/2 Keyboard
Mouse PS/2 Compatible Mouse

Network:
Network Adapter VIA Compatable Fast Ethernet Adapter
Network Adapter WPN311 RangeMax(TM) Wireless PCI Adapter (192.168.254.1)

Peripherals:
Printer HP Photosmart C4200 series (Copy 1)
Printer HP Photosmart C4200 series
USB1 Controller VIA VT83C572 PCI-USB Controller
USB1 Controller VIA VT83C572 PCI-USB Controller
USB1 Controller VIA VT83C572 PCI-USB Controller
USB1 Controller VIA VT83C572 PCI-USB Controller
USB2 Controller VIA USB 2.0 Enhanced Host Controller

Problems & Suggestions:
Problem Disk free space is only 7% on drive D:.