Here's the motherboard specs if somebody wants to chime in:
SPECIFICATIONS
Processor Supports Sempron Athlon 64 processors (Socket 754) / FSB Up to 1GHz
Chipset North: NVIDIA C51G / South: nVidia MCP51G
Memory 2 184-pin DDR DIMMs / Support DDR 333/400 SDRAM / Supports a maximum memory size 2GB
Video On board Controller Embedded in nVidia C51G / Add on interface 1x PCIe by 16
Audio Controller nVidia MCP51G / Codec ALC 655 5.1 Channels
Onboard Lan Controller+PHY--MCP51G+ Broadcom AC131 / Support 10/100 Mbps
Expand Slots One PCIe x 16 / One PCIe x 1 slot / 2 PCI
Onboard IO 1 Parallel Port / 2 PS2 Connectors / 1 x COM port ; 1 x VGA port / 1 (1 x RJ45 + 2 x USB 2.0) / 1 x Audio connectors : Mic-In, Line-In, Line-Out / 1 x (2 x USB 2.0)
Onboard IDE An IDE controller on the NVIDIA chipset provides IDE HDD/CDROM with PIO bus / Master and Ultra DMA 100/133 operation mode
System Bios ACPI, APM, DMI, SMBIOS, PnP, USB, PC99, PC2001, Y2K Compliant
USB 2.0 8 USB2.0 ports
IEEE 1394 Supports up to 2 x 1394 ports (Optional)
Form Factor uATX Form Factor - 9.6(L) x 9.6(W) (unit : inch)
Serial ATA Controlled by NVIDIA MCP51G / SATA II PORT 2 port with 3GB/s support
First of all, you are below the specs to run Windows 7 so I would go back to XP.
If you don't want to spend a lot of money and pretty much play Combat Arms(It looks like a fun game), I would just upgrade with a inexpensive video card.Maybe a ATI 5450 card.
Of course if you plan on building a new computer soon that will be a waste of money.
The PSU maybe a factor since I have no clue what PSU it uses but the lower end video cards don't use much power.
You have done some nice upgrades to that computer but you have to figure in the long run you could of put that money towards a new one.
the Prisoner