Determine what processor (CPU) you want to use for your system.Currently, the two leading CPU manufacturers are Intel and AMD (Advanced Micro Devices). It might be more beneficial to find benchmarks and compare them while factoring in the current prices.
Currently, the Intel i5 is the best option, in terms of performance to price`. The i7 is more powerful but the benefit is minimal yet the price is much higher.
A good entry-level option is the AMD Athlon II X4 640, while a good mid-range is the Intel Core i3-3220.
Find a motherboard that supports your processor. Take note of the processor socket (ex: LGA 775), the memory module type (ex: 240-pin) and the RAM frequency (ex: 1066 MHz) in choosing a motherboard. Some motherboards come with features such as HDMI and Firewire, so look for a motherboard with these features if desired.
Beware of high frequency RAM. While it may at first seem that any computer part which works harder or faster must certainly be better, this is not always the case. The benefits of high frequency RAM are inconsistent and these components are known to have a high failure rate. Consider this before you buy.
You should note the number of pins for your memory module only because of how it will connect to your motherboard. More pins does not equate with better performance. The same can be said of the processor socket: different types are not necessarily indicators of performance.
Get enough RAM to meet your needs. Having more RAM, or desktop memory, will offer smoother performance and shorter loading times. Choose memory that is within your budget from a known manufacturer. There are many different memory manufacturers, but a select few make quality memory.
You will want to choose the highest clock speed (the rating in MHz) and the lowest timings as possible (displayed in #-#-#-#) -- the performance of your computer relies greatly on them.
You will want to buy enough memory to run your applications. Understand that while your games may say that 1GB is enough, what it really means is that it’s enough to run the game badly. If you want games to run smooth, generally you should overshoot the requirement.
32-bit CPUs can only support up to 3GB of RAM; 64-bit CPUs can support much more.
DDR2 Memory runs Dual Channel, so remember to buy memory in pairs: 2 x 512MB is better than 1 x 1GB. Take note of the pin type. 184-pin sticks are DDR(1), 240-pin are DDR2. Do a bit of research on your chosen motherboard to see what it supports.
Choose a video card. This may be one of the most important, yet toughest decisions to make because there are so many different video cards on the market. Because there are so many, the best way to find your card is to look for reviews on cards within your budget. Currently the two leading video card companies are ATI and NVIDIA, but other companies such as Sapphire and eVGA are licensed to produce these cards. Use review websites such as Tom's Hardware to compare performance between video cards.
Currently, the Radeon HD 6670 DDR3 is a good entry level graphics card. The GeForce GTX 650 Ti Boost 2 GB is a good mid-range card. The GeForce GTX 780 is a good high-end option.
There have been some confusion on the NVIDIA cards, which are recommended by gamers. A higher number in the card name does not mean it is better. A GeForce 7950 would be much better than a GeForce 8500. The first number is the card series, while the second and sometimes third indicate performance level.
If you really want to pump up the game, and you have a motherboard that can support it, get 2 identical cards from the same manufacturer and run them in SLI (Nvidia), or Crossfire (ATI) mode. This is generally a bad idea, however, unless you already have a top of the line card, because it's cheaper and more efficient to get a single better graphics card.
Choose your hard drive storage. Games, audio, and videos require plenty of space to store the large files associated with media such as these. Read reviews on hard drives and choose the best for the price. Check the specs to make sure it runs at at least 7200 RPM, because you can potentially get better performance with higher values.
Faster hard drives will only affect game loading times, and even then not by much. Focus mainly on ensuring that you have enough storage space and do not prioritize hard drive speed.
SATA cards are currently the best choice because their small cables allow for better airflow and transfer speeds than traditional PATA cables.
Choose a power supply. Check the power of the power supply. Power supplies come with either 20-pin or 24-pin connectors. Get the same number of pins as your motherboard has so that it will connect. Be sure that it meets all the recommended power requirements for your parts, such as the graphics card.
A fully modular power supply is usually a good idea.
It is important to remember that most power supplies that come with cases are of low quality. Consider replacing it with one that is more powerful and more efficient as soon as possible.
350 Watts is the minimum you should expect for modern computers. More powerful components such as high-end video cards may require 500 Watts or more.
Purchase a case. Never overlook the importance of your case. After all, it houses all the expensive parts that run your computer. Here you will want to focus on cooling.
Some cases use 80mm, others use 120mm fans, and some are built for both. Generally, larger fans produce less noise and push more air through your case. More powerful components will require more cooling, so be thoughtful of which case you purchase.
If possible, you will want to have equal pressure in your case. Usually, you will want to have back fans blowing out, front fans sucking in, top fans blowing out, bottom fans sucking in, side fans sucking in.
A mid-tower case is standard, but a full-tower case may be necessary if you have a high number of peripherals, such as CD-ROM drives and hard drives.
Choose an operating system. With all the above components purchased, you will want an operating system which can make use of the system you have put together. When it has installed, check online for driver updates.
Windows tends to be the best operating system for gaming, though you may initially want to choose Windows 7 over 8, as some of your older games may have compatibility issues with the new system. This will not be an issue for any games released during and after 2013, however.
Completing and Using Your System
Make sure you put all of the parts together correctly in the case. Putting together a computer is more complex than it sounds. Make sure you do it correctly or it will not run.
Connect your computer to a high definition television. A high quality gaming PC will usually be more powerful than a gaming console. If you want the best of both worlds, connect your PC to your high def tv and you’ll get the big screen experience with the powerful PC performance.
Connect your console game controller to your computer if you prefer those controls. PC gaming controls can be hard to learn and use for people who are more familiar with console gaming. However, you can easily connect a console controller to a PC and play your game as normal.
Learn how to balance gaming and a girlfriend. With this new, awesome system, you may find it hard to pull yourself away from gaming. This can take a toll on your relationships. Learn to balance the two and keep both in your life.
Before you touch any hardware it's best to touch your computer's metal case or anything to discharge any electricity, so you don't damage your computer with voltage. You can also buy an anti-static wristband.
If at any time you do not know which part to purchase, read reviews! Remember that each reviewer has his or her own opinions and might not give the most accurate information.
Buying each part individually can be cheaper than buying a computer manufactured by Dell, Gateway, or similar companies. The more higher end a computer is, the better it is to build it than to buy it (cost-wise).
Be careful when working inside your case. Higher end cases can be generous and round the edges, while cheaper cases may leave them razor sharp.
Make sure you check all details first before you commit the purchase. Remember to keep track of your warranties. Some companies such as eVGA and OCZ offer life-time warranties. Others may only offer the retailer's warranty. This may help you save money in the unfortunate event of a hardware failure.
If you know someone who is used to working with computers, ask the for their thoughts on parts or even ask them to help you build it.
There are online bulletin boards and discussion forums that allow you to post questions and get answers from experts of varying quality. Many of your questions may be common and you may find the answers that you want already posted online. Simply type your question into a search engine such as Google and search through the answers. If you still have questions, to the forums you go!
Never force any component into place. Some components, such as power cables, may require pressure. But CPUs should never be forced into place.
When working with any computer related hardware, always keep yourself grounded! An Electro-Static Discharge may permanently damage your components. Use an electrostatic discharge wrist-strap, and connect it to a metal part of the case or other large metal object. In a pinch you can simply touch the case periodically, but this is not as reliable.