Introduction: Building a Desktop Computer From Parts

Most people buy their computers fully assembled.  How is that fun? 

I build computers from the parts because the resulting computer has exactly the features that I want.  Building a computer can save you money if you already have some of the parts from your last computer (such as a monitor, video card, keyboard or mouse).

This instructable will teach you how to build a computer. Thanks to the standardization of components building a computer is not very difficult, it is like a puzzle, most of the parts only fit in one way.

This Instructable submitted by the Rabbit-Hole Maker Space as part of the Instructables Sponsorship Program.

Step 1: Get the Computer Components

You need to gather all the basic components of a computer. I use several web sites to buy computer components, such as New Egg, Tiger Direct, Mwave, and AmazonSelecting the components to build a computer is a good topic for another instructable.

Computer components:
  • Motherboard, the most important part of the computer, all the components plug into the it.  The motherboard determines what CPU and memory you can use.
  • CPU or Central Processing Unit, the “brain” of the computer. Make sure the socket matches the motherboard.
  • RAM or Random Access Memory, stores information while the computer is running. Make sure the motherboard can handle the socket and speed.
  • Hard disk drive, stores information that is retained when the power is off.
  • CD/DVD drive, to read CDs or DVDs which is useful to install software.
  • Case, to store the computer components.
  • Power supply, to power the computer.
  • Video card, that will fit in your specific motherboard. A video card is required to play video games.
  • Monitor, to display the graphics.

  • Screwdrivers, flat head and Phillips head may be needed depending on your screws.
  • Anti static wrist strap, to protect your computer components from static discharge.
  • Screws (that should come with the case, motherboard, and hard drive).

Most computer components come in anti static bags for a reason. Always wear the anti static wrist strap and properly ground yourself before handling computer components.

Step 2: Install the Power Supply

Some computer cases may come with power supply unit (PSU). If the computer case you purchased does not, install your power supply in the empty void in the back of the case. Some cases mount the power supply on top, while others mount them on the bottom of the case. Use the 4 screws that came with your power supply (or case) to secure the power supply.

Step 3: Install the CPU on the Motherboard

If you purchased the motherboard and CPU separate you will need to install the CPU on the motherboard. Take care installing the CPU, as this is the most expensive part of your computer! Installing the CPU will involve:
  1. Raise the lever next to the CPU socket to open the retainer lid.
  2. Remove the plastic cover inside the retainer.
  3. Place the CPU in the socket correctly. Each socket is different make sure your CPU is oriented correctly (look for a triangle, or other marks to indicate correct orientation).
  4. Lower and lock the lever to secure the CPU to the motherboard.
  5. Install the factory CPU fan, by pressing it into the mounting holes on the motherboard.
  6. Plug the CPU fan into the motherboard.

Step 4: Install the RAM

The Random Access Memory (RAM) can be installed in the sockets near the CPU. Some motherboards perform better if the memory is installed in matching sockets (consult your motherboard documentation for specific information on this). So if you only have 2 RAM sticks, install them in matching sockets. Make sure to push the RAM into the socket fully so the locking levers on either side move up and are activated.

Step 5: Install the Motherboard

The motherboard needs to be securely mounted in the case. The motherboard would short out if screwed directly to the case, so install the offsets in the case.

Next install the I/O shield that comes with the motherboard.  You place this on the back of the computer case and the connectors stick through the I/O shield. Position the motherboard to line up with the I/O shield and the offsets and screw the motherboard down with the screws from the case.

Route the cables carefully around the motherboard and connect the power supply to the motherboard, there are several connectors here that only plug in one way (like a puzzle).

Some cases come with fans that will need to be plugged in to the motherboard or power supply. Also locate any front USB connector cables and plug those sockets into the proper place on your motherboard. The computer case may have power and reset buttons that need to be connected to the motherboard.

Step 6: Install the Hard Drive and CD/DVD Drive

The case will have a section to hold internal hard drives called a bay. Some computer cases may provide rails or sliders to make removing the hard drive easier or tool less. The smaller hard drives will come with adapters to make them fit in traditional sized hard drive bays. Secure the hard drive in the bay, route the proper power cord to the drive and plug in the power supply to the hard drive. Connect the proper data cable (SATA or Parallel) from the hard drive to the motherboard.

The case will have a removable cover for a CD/DVD drive. You may need to remove the cover to install the drive. Use the mounting screws that came with the case to secure the CD/DVD drive. Route the power cord to the CD/DVD drive and connect the proper data cable from the CD/DVD drive to the motherboard.

Step 7: Install the Video Card

The back of the computer case will have removable slots for extra devices. Remove the slot(s) needed to install the graphics card in the expansion slot nearest to the CPU.

Place the video card in the slot and push the video card in the socket on the motherboard. Make sure the locking lever raises up to lock the video card in place. Some video cards require additional power, so plug in the power supply to the video card.

Step 8: Finishing the Computer Build

Now is the time to double check that you have done everything correctly. Make sure all the components are connected to the power supply. Make sure all components are properly connected to the motherboard (if they need to be).  Take this time to route the cables behind the components.  Use zip ties to bundle the cables.  After making these checks you can close the case.

Connect the peripherals to the computer such as the keyboard, mouse, monitor, or network cable. Connect the power supply to the electrical outlet and you are ready to turn on the computer!

Turn the power on and enter the BIOS or the UEFI to check if everything is installed and working correctly.

The next step is to install an operating system on your computer which is a topic for another instructable.  Of course you should install a Linux operating system!  Do not be a victim of windoze.

That is it, you have built a computer!
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