One of the most crucial steps in creating a computer is choosing the parts, since you can’t put one together without them! Because of standardization, choosing computer parts has gotten lot simpler than in the past, but you still need to make sure that everything will fit. When selecting the parts for your computer, you should first consider the purpose for which it will be used. You will require very different components for a computer that you want to use for word processing and email checking than you would for a gaming computer.
CPU
What CPU you choose for your computer should be the first decision you make because it will affect the motherboard you choose and the other components you buy. Intel and AMD are the two primary CPU manufacturers. Both have advantages and disadvantages, but they are very comparable. You can get a little better value with AMD, therefore I’d advise using them.
Here is a brief overview of the diffrent Intel and AMD CPUs:
Budget: AMD: Sempron
Intel: Celeron D
Midrange: AMD: Athlon 64
Intel: Pentium 4
High End: AMD: Athlon64 X2
Intel: Pentium D
If you are spending below $500, I would suggest a budget proccesor, Between $500 and $1000, midrange and $1000 and above I would suggest a high end proccessor.
Motherboard
Building a computer requires careful consideration when selecting the motherboard. First, check sure the motherboard you choose has the appropriate CPU socket type. Next, look over the various features of the motherboards you are considering. Make sure your motherboard includes onboard video and/or sound if you decide not to purchase a video or sound card. The hard drive interface, graphics card interface, expansion ports, RAM size, and speed are further motherboard components to examine. Check for the chipset as well. Too numerous to list, but generally speaking, Intel and nVidia chipsets are superior than the competition. You know what to search for in your other components now that you’ve chosen your motherboard.
RAM
The performance and stability of your system depend on the speed and quantity of RAM you install. You will probably require at least 256 or 512Mb of RAM if you are using Windows XP. You should acquire 1Gb if you plan to perform any memory-intensive tasks, such as gaming, rendering, or if you simply want a quicker PC. Ensure that your motherboard has the appropriate number and kind of DIMMs for your RAM. Check the speed and CAS Latency as well.
Hard Drive
It’s time to choose your hard disk right now. Choosing a hard drive involves a limited number of factors. The first and most crucial factor is space; 120GB is typically plenty for the majority of people unless you plan to save a lot of photos and videos. Additionally, be sure to purchase an HD with the proper interface for your motherboard. Although SATA (Serial ATA) is a considerably quicker hard drive interface and uses a smaller cable than IDE, which helps with airflow in your case, not all motherboards feature it. There is even SATAII now, which is twice as fast. Also look at speed, almost all desktop HDs are 7200RPM and Cache, most are 8Mb, dont buy a HD below those standards. If you want to spend some money, you can get 2 HDs and run them in RAID which increases performance.
Video Cards
If you plan to game, make sure to purchase a video card; otherwise, onboard video works just fine. The interface is the first thing to look for; the most common ones are AGP or PCI-E. Personally, I like nVidia GPUs. I would recommend at least a 6600 if you plan to play graphically demanding games. Choose a 7800 if you have a lot of money to spend.
Optical/Floppy drives
Another thing you are going to is a CD drive, most are IDE. Get a DVD Burner if you are going to use it. Also, you should get a floppy drive, they are only $10ish and you might need it to install drivers when building your computer.
Case and Power Supply
Make sure you have a sufficient power supply!! If you have a high end computer, you should get a 450W PSU. Otherwise, 350W should be fine for most people. Most cases are ATX, but make sure it is the same type as your motherboard (ATX, MicroATX, BTX, etc…).
Be sure to make sure all your components are compatible!