Upgrading gaming computer

Hey guys, new here at TechSpot and I gotta say its amazing.

We all know as time goes by games become more demanding and I think its time for me to upgrade my computer. I want it to be good enough to run new games like Homefront or Black Ops. Here are my system specs:

Processor type
Intel® Pentium® 4
Intel® Pentium® D
Intel® Core™ 2 Duo
NOTE: Not all Pentium 4 processors support Hyper-Threading technology.
Level 1 (L1) cache
32 KB
Level 2 (L2) cache
1 MB for Pentium 4 5XX processors (with Hyper Threading)
2 MB for Pentium 4 6XX processors (with Hyper Threading)
2 x 2 MB for Pentium D 9XX processors (with dual core)
2 x 1 MB for Pentium D 8XX processors (with dual core)
256K for Celeron® D 3XX processors
2 MB for Intel Core™ E6400 processors and earlier
4 MB for Intel Core™ E6600 processors and later

Memory
Type
533-MHz, 667-MHz, and 800-MHz dual DDR2 unbuffered SDRAM
Memory connectors
four
Memory capacities
256 MB, 512 MB, or 1 GB non-ECC
Maximum memory
4 GB
NOTE: See Addressing Memory With 4-GB Configurations to verify the amount of memory available to the operating system.
BIOS address
F0000h

Computer Information
Chipset
Intel G965 Express Chipset
RAID Support
RAID 1 (Mirroring)
DMA channels
eight
Interrupt levels
24
BIOS chip (NVRAM)
4 MB
NIC
integrated network interface capable of 10/100 communication
System clock
533-MHz, 800-MHz, or 1066-MHz data rate

Video
Type
integrated Intel® Graphics Media Accelerator X3000 (Intel® GMA X3000)
PCI Express

Audio
Type
Sigmatel 9227

Expansion Bus
Bus type
PCI 2.3
PCI Express x1 and x16
Bus speed
PCI: 33 MHz
PCI Express:
x1 slot bidirectional speed - 500 MB/s
x16 slot bidirectional speed - 8 GB/s
PCI
connectors
two
connector size
120 pins
connector data width (maximum)
32 bits
PCI Express
connector
one x1
connector size
36 pins
connector data width (maximum)
1 PCI Express lane
PCI Express
connector
one x16
connector size
164 pins
connector data width (maximum)
16 PCI Express lanes

Drives
Externally accessible:
Bays
two 5.25-inch drive bays
one 3.5-inch drive bay (FlexBay)
Available devices
Serial ATA drives (4), floppy drive, USB memory devices, CD/DVD drive, and Media Card Reader
Internally accessible:
two bays for 1-inch high serial ATA hard drives

Connectors
External connectors:
Video
15-hole connector
Network adapter
RJ-45 connector
USB
two front-panel and six back-panel USB 2.0-compliant connectors
Audio
six connectors for 7.1 support
System board connectors:
Serial ATA (SATA)
four 7-pin connectors
FlexBay Drive
one USB 10-pin header (with one pin removed for keying) for optional Media Card Reader (3.5-inch bay device)
Floppy drive
one 34-pin connector
Fan
one 5-pin connector
PCI 2.3
two 120-pin connectors
PCI Express x1
one 36-pin connector
PCI Express x16
one 164-pin connector

Controls and Lights
Power button
push button
Power light
green light — Blinking green in sleep state; solid green for power-on state
amber light — Blinking amber indicates a problem with the power supply inside the computer. If the system cannot boot and there is a solid amber light, a problem with the system board may exist (see Power Lights).
Hard drive access light
green
Link integrity light (on integrated network adapter)
green light — A good connection exists between the network and the computer
off (no light) — The computer is not detecting a physical connection to the network.
Activity light (on integrated network adapter)
yellow blinking light
Diagnostic lights
four lights on the front panel (see Diagnostic Lights)
Standby power light
STBYLED on the system board

Power
DC power supply:
Wattage
305 W
Maximum heat dissipation
1040 BTU/hr
Voltage (see the safety instructions located in the Product Information Guide for important voltage setting information)
Manually selectable: 90 to 135 V and 180 to 265 V at 50/60 Hz
Backup battery
3-V CR2032 lithium coin cell

Physical
Height
41.4 cm (16.3 inches)
Width
18.8 cm (7.4 inches)
Depth
45.7 cm (18.0 inches)
Weight
12.7 kg (28.0 lb)

Environmental
Temperature:
Operating
10° to 35°C (50° to 95°F)
Storage
–40° to 65°C (–40° to 149°F)
Relative humidity
20% to 80% (noncondensing)
Maximum vibration:
Operating
5 to 350 Hz at 0.0002 G2/Hz
Storage
5 to 500 Hz at 0.001 to 0.01 G2/Hz
Maximum shock:
Operating
40 G +/- 5% with pulse duration of 2 msec +/- 10% (equivalent to 20 in/sec [51 cm/sec])
Storage
105 G +/- 5% with pulse duration of 2 msec +/- 10% (equivalent to 50 in/sec [127 cm/sec])
Altitude:
Operating
–15.2 to 3048 m (–50 to 10,000 ft)
Storage
–15.2 to 10,668 m (–50 to 35,000 ft)

I added two gigs of ram recently and have a nice 1 tera external hardrive aswell.
Can we try something cheaper than $1000 please?

Thanks, Rowenaj