This wikiHow teaches you how to build a desktop computer using custom parts. Successfully building a computer is largely contingent on defining your computer goals and budget, buying the right parts, and putting everything together in the correct order.
1
Determine your computer's use. Before you buy any components or establish a budget, you'll need to know what you plan on using the computer for. Standard desktop PCs which are used for things like browsing and minor programs (e.g., Microsoft Word and Excel) can use older, less expensive parts, while gaming- or editing-focused computers will need more powerful, up-to-date parts.[1]
Note: You can expect to spend under $500 for most basic desktops. Gaming and editing computers may run you anywhere from $500 to several thousand dollars.
2
Establish a budget. It's too easy to start buying attractive parts without sticking to a budget, only to realize that you're out of money and don't have all of the necessary equipment to build your PC. Figure out a soft limit (e.g., $300) and a hard limit (e.g., $400) and try to stay within that range.
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3
Know which components you need to buy. No matter how expensive your computer, you will need the following components for your project:[2]
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1
Know where to buy components. In-store locations such as Best Buy will stock computer components, but you can usually find comparable parts for cheaper if you shop online. Common online locations include Amazon, eBay, and NewEgg.
2
Research every component you intend to purchase. Read magazines and online consumer review sites for more information. Remember, this is one of the most important steps, because everything will depend on your hardware working correctly.
3
Find a processor. The processor (or CPU) is the core of your computer's performance. The higher the processor's speed in gigahertz (GHz), the faster it can process data. Many applications use multiple threads at the same time, so more cores can improve performance.
4
Get a motherboard which fits your processor. You'll want to select a motherboard which is compatible with your processor, which can be accomplished by checking the socket of the CPU and motherboard. Other aspects to look for in a motherboard include the following:[3]
5
Purchase RAM. RAM is responsible for storing data from running programs, so having enough of it is important. Before buying RAM, be sure to check both your processor and your motherboard for the type of RAM which is supported.[4]
6
Buy a hard drive. Comparatively speaking, purchasing a hard drive is easy—most hard drives are compatible with virtually all motherboards and processors, though you may need to make sure the hard drive you find will fit in your case. You'll want to buy a SATA hard drive which stores at least 500 gigabytes, and be sure to buy from a reputable manufacturer such as Western Digital, Seagate, or Toshiba.
7
Purchase a graphics card if necessary. A dedicated graphics card is essential for playing the latest games, but not a major issue for a computer you plan on using for daily tasks. If you watch or edit a lot of HD video or play a lot of games, you'll want a dedicated graphics card.[5]
8
Make sure your power supply can handle the load. The power supply powers all of your components in your computer. Some cases come with a power supply already installed, but others require you to provide your own. The power supply should be powerful enough to charge all of your components; don't worry about it being so powerful that you waste electricity by powering more than you need, as it will only output as many watts as you use and the number on its wattage is only its max capacity.
Tip: Choose a power supply from a reputable manufacturer like Seasonic, beQuiet, EVGA or Corsair.
9
Pick up a case that is both functional and easy on the eyes. The case is what holds your computer components. A few cases come with a power supply included, but if you are making a gaming build then getting a separate power supply is recommended, as the power supplies that come with cases are usually not very high quality.[6]
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1
Ground yourself. Use an antistatic wrist-strap cable to prevent electrostatic discharge (ESD) which can be deadly to computer electronics. Alternatively, touch a large metal body like a radiator to discharge yourself.
2
Open the case. Unscrew the side panel (or slide it toward the back of the case) to do so.
3
Install the power supply. Some cases come with the power supply already installed, while others will require you to purchase the power supply separately and install it yourself. Make sure that the power supply is installed in the correct orientation, and that nothing is blocking the power supply's fan.[7]
4
Add components to the motherboard. This is usually easiest to do before you install the motherboard, as the case can limit your ability to wire components:[8]
5
Apply thermal paste to the processor if necessary. Put a small dot (around the size of a grain of rice or a pea) of thermal paste on the CPU. Adding too much thermal paste will create a mess, such as getting paste into the motherboard socket, which may short circuit components and decrease the motherboard's value if you plan to sell it later.[9]
Tip: Some processors that come with heat sinks do not need thermal paste because the heat sink already has thermal paste applied by the factory. Check the bottom of the heat sink unit before applying paste to the processor.[10]
6
Attach the heat sink. This varies from heat sink to heat sink, so read the instructions for your processor.[11]
7
Prepare your case. You may need to knock the plates out of the back of the case in order to fit your components into the correct positions.
8
Secure the motherboard. Once the standoffs are installed, place the motherboard in the case and push it up against the backplate. All of the back ports should fit into the holes in the I/O backplate.
9
Plug in the case connectors. These tend to be located together on the motherboard near the front of the case. The order in which these are connected will depend on which is easiest. Make sure that you connect the USB ports, the Power and Reset switches, the LED power and hard drive lights, and the audio cable. Your motherboard’s documentation will show you where on your motherboard these connectors attach.[12]
10
Install your hard drive. This process will vary slightly depending on your case, but should typically go as follows:[13]
11
Connect the power supply to any necessary components. If you haven't already connected the power supply to components which need power, make sure that it is connected to the following locations:
12
Finish your computer assembly. Once you've placed and connected the various internal components for your computer, all that's left to do is ensure that none of the wires interfere with circulation and close up the case.
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1
Attach your computer to an outlet. Using your power source's power cable, plug your computer into a wall outlet or power strip.
2
Plug a monitor into your computer. You'll typically use the graphics card output that's near the bottom of the case, though some motherboards may have this port on the right or left side of the case.[14]
3
Turn on your computer. Press the computer's Power
button on the front or back of the case. If everything's properly connected, your computer should start up.
Tip: If you encounter issues during the startup process—or if your computer fails to start—disconnect it from the power source, re-open the case, and check the connections again.
4
Install Windows or Linux. Windows is compatible with all PCs and will make full use of their various features (e.g., Bluetooth), but you will have to purchase a copy of Windows if you don't have a product key. Linux is free, but may not be able to use all of your computer's hardware.
5
Install your drivers. Once your operating system is installed, you will need to install your drivers. Almost all of the hardware that you purchased should come with discs that contain the driver software needed for the hardware to work.
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Question
Where can I get price comparisons for computer parts?
Community Answer
Use a website called PCpartpicker.com It will help you choose compatible parts and also determine the cheapest website to buy from.
Question
How do I install an OS?
Community Answer
Because most OSs nowadays are booted from USBs, you will need to change the start-up order (in BIOS) to start from the USB. There will usually be on-screen instructions aiding you with installing your OS.
Question
Is it possible to get Windows without having to insert a disc into your optical drive? If yes, how?
Community Answer
Windows 10 purchased from a store or online comes on flash drive now, all you have to do is plug in the flash drive and boot from that. You can also download the ISO and, using Microsoft USB Download Tool software, create your own bootable installation flash drive if you have a spare.
Question
After building my PC with all new parts, I plugged it in but only got power for a second then nothing, what went wrong?
Community Answer
It's possible that there is a grounding issue with the motherboard. If the motherboard is contacting the case, it creates a path to ground, which kills the electric charge in the circuits. Check to make sure there are spacers separating the motherboard from the metal of the case.
Question
What is thermal paste for?
Community Answer
Thermal paste is a very good conductor so it transfers heat from the CPU to the heatsink more effectively than without it. Even though metal is a good conductor, there can be imperfections on the metal which will reduce conductivity leading to heat being built up in the CPU.
Question
Can I put two separate CPUs in a motherboard non-dual/quad core or is there not enough space?
Community Answer
It is impossible for you to do that unless your motherboard already accepts two CPUs.
Question
What if the CPU doesn't go in?
Community Answer
Check the arrow on the bottom left part of your CPU, and line it up to the little arrow on your motherboard. It should just drop in. If not, you might have bought the wrong motherboard for your CPU.
Question
Do I need a heat sink too?
Community Answer
Yes. You need a heat sink to prevent the computer from overheating and shutting down automatically.
Question
Is a heat sink the same as a CPU cooling fan, or does it come with it, or do I need to purchase it separately?
Community Answer
Most of the time, a CPU comes with a heatsink, but if it is Intel and has a K on it (ex. Core i7 6700k, Core i5 6600k), you will most likely need to buy a separate fan.
Question
Can I install a hard drive that already has an OS on it?
Community Answer
Yes, when you want to run that OS you will have to go into the BIOS or boot option menu to tell the computer to boot from a specific hard drive. If you are keeping a hard drive from an old computer, make sure it is compatible with the new parts and try to do a fresh install of the OS to wipe out any bloatware.
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Some components will come with protective plastic on them so they aren’t scratched up. Make sure you remove this or you computer will start to smell like burning plastic.
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Each power supply cable will only fit in the correct orientation, but pressure will still be needed to push the cables in. If using a newer power supply with an 8-pin EPS 12V connector and a PCI Express 8-pin connector, don't attempt to force the cables into place.
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If you install a water cooling system instead of a typical fan, you should run a 24-hour test to check for leaks before actually installing it in your computer.
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You can use zip ties to carefully bundle all of the cables and then route them to prevent them from blocking the airflow.
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If you bought an original equipment manufacturer (OEM) edition of Microsoft Windows and you have a license sticker, you may want to attach the sticker on the side of the PC for future reference when Windows Setup asks for it.
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Some power supplies have a built in 115/230V converter. If you are in the U.S., use the 115V setting.[15]
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Avoid electrostatic discharge when installing components. Wear a static wristband or regularly ground yourself by touching a metal part of the case before handling components.
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Make sure all parts are compatible with your motherboard!
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Do not buy any computer parts from any untrusted retailer online; you might get scammed, or the computer part may be defective.
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Use care when working around the sharp, sheet metal edges of a computer case. It is easy to cut yourself, especially with very small cases.
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Don't touch the resistors and the pins on the CPU or the socket.
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Be sure to buy a power supply with the specific needs for your system and from a reputable company, as cheaper ones can be faulty and completely damage your system.
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Wash your hands before building a computer.
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To build a computer, start by grounding yourself with an antistatic wrist-strap cable to prevent electrostatic discharge. Next, open the case and install the power supply near the top of the case. Then, attach the processor and RAM to the motherboard, hook it up to the power supply, and attach the heat sink. Once the standoffs are installed, place the motherboard in the case, push it up against the backplate, and secure it with screws. Finally, install the hard drive and make sure the power supply is connected to all of the necessary components before connecting the monitor. To learn more about which components to buy and where to buy them, read on!
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Matthew Lennartz
Apr 1, 2017
"While majoring in Computer Engineering, the majority of my IT career was, unfortunately, spent in the auspices of..." more
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