I know i may seem noobish but all i want is a decent gaming computer (CoD4 all high details at least 60 FPS lol) and this is my first rig to build (haven't bought anything yet except the Graphics card this is the blue print though) here are my specs :B

ASUS M4A785-M Motherboard Price: $180 (combo with processor)

Compatibility PC
Chipset AMD 785G
Compatible Processors AMD Athlon, AMD Sempron, AMD Phenom, AMD Phenom II
Front Side Bus Speed 2600 MHz
Technical Features
Integrated Input/Output Ports RJ45 Lan Port x 1 • PS/2 Mouse x 1 • PS/2 Keyboard x 1 • USB 2.0 x 12 • HDMI x 1
Expansion Slots PCI Express x16 x 1 • PCI Express x1 x 1 • PCI x 2
RAID Support JBOD Support • SATA RAID 0 • SATA RAID 1 • SATA RAID 10
Storage Controller Type(s) DMA/ATA-133 (Ultra) x 1, Serial ATA II x 6
South Bridge Chip Unknown
Processor
Socket Type Socket AM2
Max supported CPUs qty 1
Memory
Memory Type DDR2 SDRAM
Number of Memory Slots 4 x 240 Pin DIMMs
Supported RAM speeds 800 Mhz • 667 MHz • 1066 MHz • 1200 MHz
Max Supported RAM 16 GB
Audio / Video
Audio Output SPDIF Out • 7.1 Channels
Integrated Audio VIA Vinyl VT1708S
Video Out Ports DVI x 1 • HDMI x 1
Video Interface PCI Express
On Board Graphic Processor ATI RADEON HD 4200
Communication
Networking Type Gigabit Ethernet
Other Features
Other Features Dual Channel Memory Architecture • 64bit Ready
Fans 1 x Fan
Chassis Type Desktop
Package Qty 1
Dimensions
Depth 9.6 in.
Width 9.6 in.
Miscellaneous
Bios Features Plug And Play BIOS • DMI2.0 • WfM2.0 • ACPI 2.0a • SMBIOS 2.5
Power Configurations ACPI/APM Power Management
Bios Type 8 Mbit Flash EEPROM with AMI BIOS

MD Athlon II X4 620 Quad Core Processor Price: $180 (combo with motherboard)

Key Features
Front Side Bus Speed 600 MHz
Processor Type Athlon
Socket Type Socket A
Processor
Manufacturer AMD
Processor Type Athlon
Clock Speed 2.8 GHz
Memory
L2 Cache Size 2 MB

RAM Price:$188 (i will buy 2 at first then upgrade as i get the money )

4 x 2GB Kingston dimms

Specifications
Memory Category: Desktop
Memory Type: DDR2
Memory Speed: PC5400
Memory Speed MHz: 667MHz
Memory Size: 2048MB
Total Memory Size: 2GB
Memory Modules: 1
Memory Channels: Dual
Memory Socket: DIMM
Memory CAS Latency: 5
Pins: 240

BFG 450-Watt ATX Black Power Supply Price:$30.00

Specifications
Form Factor: ATX
Wattage: 450-Watt
Fan: 140 mm
+3.3V: 22 A
+5V: 15 A
+12V 1: 18 A
+12V 2: 18 A
-12V: 0.3 A
+5VSB: 2.5 A
20+4-Pin Connector: 1
Motherboard Connector: 20+4 Pin
6-Pin PCI-Express Connector: 1
4-Pin Floppy Connector: 1
SATA Power Connector: 2

Western Digital WD7500AADS Caviar Green Hard Drive Price: $70
Specifications
Drive Type: Internal
Capacity: 750GB
Interface: SATA 3.0Gb/s
Interface Type: SATA
Spindle Speed (RPM): Intellipower
Buffer Memory: 32MB
Data Transfer Rate on Serial ATA: Up to 3000 Mb/sec
Form Factor: 3.5"
Temperature, Operating (°C): 5 to 55
Temperature, Nonoperating (°C): -40 to 70
Shock, Operating: 2 msec (Gs): 65
Shock, Nonoperating: 2 msec (Gs): 300
Acoustics Idle (bels—sound power): 24 dBA
Acoustics Seek (bels—sound power): 25 dBA
Acoustics Performance Seek (bels—sound power): 29 dBA
Dimensions: 1.02" x 4.00" x 5.79"

Diablotek EXDVAKP External Slim DVD Drive Price: $55

Specifications
DVD-R Write Speed: 8X
DVD-RW Rewrite Speed: 8X
DVD Read Speed: 8X
CD Write Speed: 24x
CD Rewrite Speed: 24x
CD Read Speed: 24x
Color: Pink
Length: 5.4"
Width: 5.3"
Height: .63"
Weight: .85 lbs
Load Type: Tray
Interface Type: USB
Enclosure Type: External
Compatible Writable Media: CD-R, CD-RW, DVD-R, DVD-RW
Supported Formats: CD-R, CD-ROM, CD-RW, DVD-ROM, DVD-R, DVD-RW

Diamond Radeon HD 4670 Video Card Price: $140 with shipping (will replace the motherboards current one since i already bought this one -_- may sell the replaced one for extra cash.)

Specifications
Lifestyle: Performance
Chipset: ATI Radeon
GPU Series: ATI Radeon HD 4000
GPU/VPU: RADEON HD 4670
Additional Features:
HDCP Enabled
Game Physics Capable
ATI Avivo HD Technology
Video Memory: 1GB
Memory Type: GDDR3
Memory Interface: 128-bit
Stream Processors: 320
Core Clock: 750 MHz
Memory Clock: 900 MHz
Interface Type: PCI Express 2.0
Interface Speed: x16
Connector(s): Dual DVI (Dual Link)
HDTV/S-Video
HDMI (w/ Adapter)
Multiple Monitors Support: Yes
Multi-GPU Support: CrossFire-X
Overclocked: No
APIs: OpenGL 2.0
DirectX 10.1
Shader Model 4.1
1080p Support: Yes
Video Output: DVI
S-Video
Low Profile: No
Cooling Type: Fan, Heatsink

Casing: PS2 case cuz i feel like it and if not enough space for all that i will put 2 on top of one another hot glued together. Price: forgot lol its been 3 years

OS:... not sure? idk which to choose between Vista or XP (i dont do mac even though i do like them and 7 is too new)
I know Vista is a resource hog but i kinda love the way it looks? and I am REALLY familiar with XP but i feel its getting old. Not sure what to decide but odds are the price will be 100-150 for OS CD. I know it will be 64-bit obviously from the amount of ram i want to use . I would also like input on OS cuz ... I just DONT know which to pick XD. Leaning towards XP though because of the vista resources issues.

D-Link - DGE-530T Network Card Price $40

Interface: PCI
Port Type: RJ-45
Number of Ports: 1
Protocol: IEEE 802.1p
IEEE 802.3
IEEE 802.3u
IEEE 802.3ab
IEEE 802.1q
IEEE 802.3x
Data Transfer Rate: 1000Mbps
10Mbps
100Mbps

Corsair CWCH50 Hydro H50 CPU Liquid Cooler Price: $75

Specifications
Fan Type: CPU Water Cooler
Fan Speed: 1700 RPM
Heatsink Material: Copper
Fan Dimensions: 120 x 120 x 25 mm

I'd pretty much prefer ALL parts to be internal -_- I don't like fiddling with things on the outside.. it's too tedious.

Total Price: $650-700

If i am missing any crucial or necessary parts plz tell me -_- think i covered all the normal stuff besides obvious things like monitor, mouse/keyboard, etc. Oh, and any compatibility problems too :S sorry im new so i like being cautious about this. I has the knowledge to put one together though .

If you made it through all that you are a trooper , and thanks so much for helping me! I am only 15 so making enough money to afford all this took half a year so i dont' want to RMA something and have all my money go down the drain X.xIt has been a few years since I played FPS games on my PC. (I made the move to consoles.) But I remember what it's like to save up for a new rig. You don't want to be disappointed. With that in mind, since you mentioned CoD4 specifically, you need to read this article:
http://www.gamespot.com/features/6183967/index.html

Personally, I'm a fan of Intel CPUs. Whatever brand you go with, if you want to play newer games with all the details up, think about a faster processor. Just a thought. I would also consider a faster HDD. The Green models aren't really known for speed. While the one you chose spins at 7200RPM, I think you will notice better performance if you go with Caviar Black. You can always go tops with a 10K or 15K drive, but cost is definitely high. Main benefit of a faster HDD is faster load times when the game starts and GOING between levels. It won't impact your frames PER second.

Final recommendation is on the OS. I don't think you'll find 64-bit XP, and if you do, I wouldn't recommend it. 64-bit consumer desktops really became mainstream after XP was LAUNCHED, so Microsoft had to "retrofit" 32-bit XP to offer 64-bit support. That's my opinion. I'd just go with Win7. It really is just Vista with good improvements. Yes, it's true that waiting for the first Service Pack is a good idea, but in this case, I say just go for it.

Whatever you buy, I recommend checking out www.newegg.com for pricing if you haven't already. Also, this should be a fun experience. I like that you're putting it all in a PS2 case. Have fun and good luck!

P.S. I'm typing this on a very tiny keyboard, so I apologize for errors.