How to Build a Computer

This tutorial is aimed at helping you to build your own computer. There are many different combinations of hardware you can have. We will deal with the basics to enable you to get a computer up and running.


Tools Required

Philips Crosshead Screwdriver, Overhead light source, Tweezers, Wrist strap to attach you to case

Hardware Required

PC Case, Floppy Disk Drive, CD Rom Drive, Hard Drive, Motherboard, Processor, Processor Heat Sink(fan), RAM, Power Supply, Video Card, Keyboard and Mouse


Software Required

Operating System, Drivers (come with hardware), motherboard CD

Cables and Extras

Drive Cables, Screws (usually with PC Case), CPU Cooling Compound, Power Cords for computer and monitor

Step 1…Install Power Supply Unit (PSU), CPU, and Heat Sink on the motherboard

Remove the case cover by unscrewing the four to six screws and taking the cover off. Lay the case on its side with the metal backplate facing up to you. Some cases come with a preinstalled PSU others do not. Slide the PSU into place with the wires facing forward into the case and the fan blowing out the back to install a PSU. Secure it in place with some screws so that it does not move. Set the voltage to 220 in the UK, 120 USA. The backplate may need changing to match your motherboard. To do this, break off the old plate and take the new plate (packed with the motherboard) and install it in place of the old one.

The motherboard should be sat on a secure surface in/on the antistatic bag it came in. To install the CPU, make sure the lever on the motherboard is up (refer to the manual supplied with your motherboard to see how this is done). Take the processor out of the box it came in by only touching the edges of the chip. Place this into the socket by matching pin 1 to the correct place on the motherboard. Usually, a gold arrow lines up with another mark on the socket. Once in place, Push the lever arm down to lock the processor in place.

To install the Heat Sink/fan onto the processor, clean the processor with a lint-free cloth to remove dust and finger oil. Take the cooling compound and squirt a small amount onto the processor directly, taking care not to use too much as it may go over the edges. Spread this evenly over the surface of the processor. Take the Heat Sink and place it directly on top of the processor, pushing down slightly to ensure a good connection between the processor/compound and Heat Sink. Using the clips on either side of the Heat Sink, secure this in place on top of the processor. Check that no cooling compound has leaked from the sides; otherwise, you have to start again and clean both the Processor and Heat Sink. Once the Heat Sink is in place, plug the power cord attached to it into the motherboard. See the manual supplied with your motherboard to determine which one. This is step 1 complete.

Step 2…Install memory modules (RAM) and Motherboard into the case.

To install the memory modules, Attach the antistatic wrist strap to an unpainted metal surface to earth yourself and discharge any built-up static. On the motherboard, you should see the slot for the memory module. , Please pick up the memory module by the edges and place it into the slot by lining up the notches and making sure both ends are in the clips. Make sure the clips at either end are open, i.e., tilted backward. Push down firmly, and the clips should pop shut. This is the memory Installed.

The motherboard should now have the processor, Heat Sink, and memory installed. The motherboard can now be placed into the case. To install the motherboard into the case, look at the holes on the motherboard and the holes on the motherboard plate in the case. Take the motherboard standoff screws and screw them into the motherboard plate in line with the holes on the motherboard. Once this is done, take the motherboard and place it into the case with the inputs and outputs facing toward the case’s back. These should fit into the backplate of the case. Take some screws and screw the motherboard into the stand-offs. Do not screw too tightly; otherwise, the circuits on the motherboard may break but enough, so there is no movement. Step 2 is complete.

Step 3…Connect the Motherboard to the Case Wires and PSU

Now the motherboard is in place, take the 20 or 24 pin connector from the power supply and connect it to the motherboard. The board may also require a 4 Pin connector to power the CPU. Plug this in too. The case should also have a set of wires which will plug into the motherboard. Refer to the manual supplied with your motherboard to install these correctly. Usually, the connector labeled PWR_SW is the power switch, and RST is the RESET button. The Power LED and Hard Drive LED must also be attached. Once all the connectors are connected, move to Step 4.

Step 4…Install the Floppy Drive, Hard Drive, and CD-ROM Drive

To install the floppy drive choose which drive bay you want the floppy drive in and remove the faceplate on the case. Slide the drive in from the front and make sure it lines up with the faceplate and the screw holes on the mounting rack. Screw the drive into place. Connect the power supply to the floppy drive. This is the smallest connector coming out of the PSU. Take the ribbon cable and attach it to the back of the floppy drive; this cable has a twist in it. Attach this to the motherboard lining up the red edge. If you do not line this up, the drive simply won’t work. When attached to the port on the motherboard, the floppy drive is installed.

To install the Hard Drive determine which bay you are going to put it in. Slide it in from the back and match up the screw holes to the mounting plate. When this is done, secure it in place. Attach the 4 pin Molex connector from the PSU to the back of the drive; it will only fit one way. If the drive is IDE, it will have a big connector on the back. If this is the case, take the ribbon cable and attach this to IDE 1 on the motherboard. If the drive is SATA, the connector will be much smaller and the cable a lot thinner. If this is the case, take the cable and attach it to the back of the drive, then to SATA_1 on the motherboard. This is the hard drive installed.

To install the CD ROM drive, this is very similar to the floppy drive. Choose which bay you want it in and take the faceplate off. Slide the drive in from the front and screw it into place. Attach the 4 pin Molex connector as you did with the hard drive, and then take the ribbon cable and attach this to IDE_2 on the motherboard. This is Step 4 complete.

Step 5… Install the Video Card

A video card is required so that you can see the output from your PC. There are two types used older AGP cards or newer PCI Express Cards. To install a Video Card, you should see a brown slot known as an AGP slot. If your card is AGP, then it goes here. Open the slot at the back of the AGP slot. There may be a clip like with the memory modules; this supports the card as they are now quite big. Break off the metal covering the hole at the back of the case. Take the video card by holding the edges only and slot it into this port and press down firmly; you should feel it click into place. Do not over force it as this may damage the circuits and your motherboard. Once in place, secure the card by screwing it to the back of the case. You should see this on the metal plate at the back. Some Video Cards require additional power now, so attach the 4 pin Molex connector to the video card. This is the Video Card Installed.

For PCI Express, follow the above but use the PCI Express slot instead.

Step 6…The initial boot up and configuring the bios

Well done, you have now completed building your computer. It is now time to see if the thing works!!! Plugin the computer and attach the mouse and keyboard. Before you hit the power button, here is what to look for: The PSU and Processor fans Start spinning, The power LED comes on, The Hard Drive boots up. You may hear a beep from the PC speaker. If you hear multiple beeps, this means there is an error somewhere. If there are strange grinding sounds, then turn off the computer immediately.

Turn on the computer; if you see the bios screen hit the appropriate key to enter the bios and check if everything is working properly. If this is the case, then set the boot device to CD. Congratulations, you have now completed building your computer.


Alcohol scholar. Bacon fan. Internetaholic. Beer geek. Thinker. Coffee advocate. Reader. Have a strong interest in consulting about teddy bears in Nigeria. Spent 2001-2004 promoting glue in Pensacola, FL. My current pet project is testing the market for salsa in Las Vegas, NV. In 2008 I was getting to know birdhouses worldwide. Spent 2002-2008 buying and selling easy-bake-ovens in Bethesda, MD. Spent 2002-2009 marketing country music in the financial sector.