How to Build a Desktop Computer

How to Build a Desktop Computer


I wanted to upgrade my ten year old desktop but found that what I wanted and what I could afford were two completely different things. Therefore, I decided to look into building my own Desktop and after some considerable research decided to purchase the following as the basic parts for my desktop:-

  • AMD Athlon II X4 640 Socket AM3 3GHz 2MB L2 Cache Retail Boxed Processor
  • Asus M4A88T-V EVO/USB3 880G Socket AM3 On-board 128MB Memory DVI VGA HDMI Out ATX Motherboard
  • Hitachi Deskstar 1TB Hard Drive SATAII 7200rpm 32MB Cache – OEM
  • Sumvision PowerX2 700W PSU - 2x SATA 1x PCI-Express
  • Microsoft Windows 7 Home Premium - Licence and media - 1 PC - OEM - DVD - 64-bit – English
  • Kingston 4GB (2x2GB) DDR3 1600MHz HyperX Blu Memory Kit CL9 1.65V
  • Casecom LG-3320 Piano Black Mid Tower Case - No PSU - Front USB2.0/Audio

In addition to the above I decided to install a DVD Player/Recorder and a Card Reader. Here I made a small mistake in that the DVD Player had IDE connections rather than SATA and therefore would not operate quite as quickly. However, this was not consider to be of any great significance. Otherwise, all connections meet the SATA requirements.


Firstly I had to decide whether to use an Intel or AMD based system. Clearly Intel have a great reputation but tend to be expensive. On the other hand AMD are very good and are less expensive. Moreover, my present desktop uses an AMD processor and I have had no trouble with it. Accordingly I decided on AMD. This meant I had to use a motherboard which will run with the AMD processor.

As far as the Motherboard was concerned I did not want a “gaming” PC and therefore opted for an integral motherboard giving me both graphics and sound. In addition I wanted a motherboard that had AM3 connections to receive the AMD processor and would handle the clocking speeds required. Furthermore, the motherboard had to be in the ATX format to fit into a dedicated ATX mid-tower case.

Then I turned to the hard drive. Here I wanted a good quality drive which would have a capacity of 500GB. However, the difference in cost between that and a 1TB drive was so minimal that I thought I might just as well go for the latter.

When considering the Power Supply it seemed to me that a 450W unit would be adequate, however, I knew I wanted to add some further hardware, such as the DVD Player/Recorder and the Card Reader, so I thought I should build in some further capacity to handle this and to handle possibility of running the computer harder than I had first imagined. I therefore settled on the 700W Sumvision Power X2 which is more than adequate for my needs.

I am proposing to run this computer as a dual boot system and therefore decided to use Windows 7 and Ubuntu 10.10 as the two operating systems, hence the purchase of Windows 7. I have Ubuntu 10.10 as a free download on disc. Ubuntu 10.10 is to be found otherwise as a free download from Canonical.

I included 4GB of memory and after considering all the options chose the Kingston 2x2GB arrangement with heat sinks because these were cheaper than a single 4GB card.

Finally, I could not see the need to buy an expensive case and the one I chose accepts the ATX motherboard and has more than adequate room for all the units to be mounted in it as well as further fans if need be.


With all the parts available where does one start? Well I started with the motherboard because its easier to construct this outside the case. The main piece of hardware to be added is of course the processor and then the processor fan and heat sink which are included in the package with the processor.

Firstly I located where the processor is to be mounted. This is the only large square connector mounted on the board. There is a thin wire like arm which sits along one side of the connector and I carefully moved this to one side away from its lock and then upwardly through 90 degrees.

I found the processor to be of a flat rectangular shape with a plate on one side and pins on the opposite side. A cut-out was provided across one corner of the processor so that when mounting the processor on it's connector on the motherboard the cut-out is aligned with a similarly shaped lip on the connector. Taking care not to touch the plate or the pins to avoid any subsequent electrical malfunction, the processor was correctly located on the connector and the wire like arm moved down towards the board and relocked in place. This ensures the sockets in which the processor pins sit tightly clamp the pins providing a good electrical connection and securely holding the processor in place.

Next I added the processor fan and heat sink. These are a single unit which can be mounted in one of two ways determined by two links which serve to lock this unit in place over the processor. The best way round depends on the power lead for the fan and whether it can reach its connections on the motherboard. Moreover, because you do not want this lead, in use, to obstruct the fan it is advisable hold it in some way and one way is to run the power lead behind the nearest fixing link and the heat sink. However, take care to ensure this cable does not touch the heat sink. Fix the links over the small hooks provided on the processor connector on the motherboard and move the locking arm associated with one of the links through 180 degrees to lock the heat sink and fan securely to the processor/motherboard.

I next mounted the Kingston memory cards in two of four slots provided on the motherboard, two blue and two grey. However, I first had to decide which of the four slots to use and a quick look at the manual that came with the motherboard showed the blue slots to have the better performance and consequently I mounted the memory boards in the blue slots. To mount the memory boards it is first necessary to push outwards the clip arm at each end of each slot, then align the contacts on the card with the slots and push the card firmly, but evenly, along its length until the clip arms snap back into position locking the cards in position. The alignment is easily achieved because the contacts on each card are divided into two sets with a clear division about one third of the way along the card. The slots are similarly divided so that the cards can only be inserted into the slots one way.

I now removed both sides of the case and lay it on one side for easy access to the area where the motherboard is to be attached. I also made sure I had easy access to what will be the rear of the case.

I picked up the motherboard by the processor heat sink and located it roughly where it should go in the case with the external connections pointing towards the rear of the case. Immediately I noticed that these connections did not align with the holes supplied for these external connections in the rear of the case. However, my motherboard came with an appropriate plate for the external connections and to make use of it I pushed out the plate on the case and inserted the plate supplied into the resultant aperture. Once this had been completed the motherboard was located in position with its fixing holes located over appropriate screw threaded bosses provided in the case. These threads are all raised to isolate the bottom of the motherboard from the metal case other than at two locations. Fortunately, two bushes were provided for this purpose with all the fixing screws that came with the case. When these bushes were located I screwed the motherboard in place.

The order in which all the items are fitted into the case is open to debate being a matter of choice bearing in mind the space available in the case. In this build the motherboard went in first followed by the Power Supply unit with all its leads and connectors for the various units, particularly the motherboard. Even to the experienced hand the connection of the power supply to the motherboard can be confusing and it is highly recommended reference be made to the manual that is provided with the motherboard. These days such manuals are clearly laid out and the connections from the power supply clearly labelled.

With the motherboard and power supply in situ I inserted and fixed the hard drive, with screws provided, in an internal 3.5in bay near the front of the case. This was followed by the mounting of the DVD player and card reader in 5.5in bays at the front of the case. To achieve the latter I first had to remove from the case a plastic faceplate and then a metal blanking plate to allow insertion of the DVD player and Card reader into the case.

Once everything was fixed in place I checked all connections and fixed the side panels on the case to complete the build.

The PC was now ready for connection to the mains, so I attached a monitor and a keyboard, connected to the mains, and then switched the PC on. All being well and this being a new build there is of course no operating system so I continuously pressed the delete key to enter the bios. Once into the bios I used the up/down, left and right arrow keys to navigate around the screen to set the order of booting the computer to be from CD first. This ensures that when the install is begun the Operating System, in my case Windows 7 or Linux Ubuntu 10.10, the install will boot from each of their respective discs.

The big question now is which of these Operating Systems do I install first? I was tempted to install Linux first since this is a relatively simple install. However, I am advised by the infinitely more experienced members of SOSLUG that it becomes much more difficult and complex to partition the hard drive when following that course, and that partitioning will be easier by installing Windows first.

Accordingly, I installed Windows 7 first. This was a straight forward process and I must say surprisingly easy, just make the choices presented to you as you see fit. The time taken to complete the basic install was about 40 minute. At no point in the install did the question arise of partitioning the hard drive. However, the install allocated the whole of the drive to Windows 7.

I retrieved the Windows disc and inserted the Ubuntu 10.10 disc. Initially I completed some basic settings as they arose and then the install recognised that partitioning was required. A partition window appeared showing that,as mentioned above, Windows 7 had in effect used the whole disc.

I should say here that I proposed to partition the 1Tb hard drive with Windows 7 taking say 300Gb, Linux 10.10 20Gb, a home partition of approximately 300Gb, and a shared partition of 300Gb.

Before proceeding with the partitioning I recommend you take note of the following warnings if you are going to use a previously used drive which has data stored on it. However, if like me you are using a new drive you need not worry:


  2. Existing partitions can be resized successfully, but nothing can be guaranteed, so abide by warning 1, and

  3. If you want to dual boot Linux and Windows 7 as I did, make sure you have de-fragmented Windows first. Windows is extremely messy in the way in which it writes files to the hard drive and if you are going to resize the drive it is essential you tidy them up first. In my case I did not have to do this because I installed a new version of Windows 7 onto a new disc, and subsequently then installed Ubuntu 10.10.

OK, on to business!

There are in essence three options open to you :-

  • If you already have a spare partition that's free, you can use that. Just select it, and let the wizard carry out it's work.
  • If you really are sick of Windows (or it's a new drive) you can choose to use the whole of the drive for Ubuntu 10.10,or
  • You can use the Custom disk partitioning.

In my case I wanted to dual boot between Windows and Linux so therefore I used option c) and as described above the introduction of the Ubuntu disc had presented me with a partition window similar to that shown below.

However, you may find similar representations with the graphical and tabular portions of the page transposed.

Right click on the single Windows partition and from the menu that appears select Resize. A disc management window then appears which tells you how big the partition is, how much space is being used and what space is left to add one or more new partitions. Use the boxes relating to these features to reset the partition volume as you want it. Remember to leave sufficient space in a partition to load any further programs you may wish to download and accommodate any large folders you may have.

Repeat the above process to set partitions in the same manner for the Linux OS, a Home partition for Linux and a Shared partition into which data from both Windows 7 and Linux can be saved and shared. All these partitions are created within the free space just created from the resizing described above.

Notes: while the “shared partition” could be formatted as ntfs, even at the time of writing, Linux can struggle with ntfs (although it's improving all the time). It is therefore recommended to format the shared partition as FAT32.

The Linux OS and Home partitions should be formatted in a native Linux format such as ext3 (or whatever you prefer). It is also worth mentioning, with 4GB of RAM available, a swap partition is not necessary.

Although on this installation I have chosen to mount Home in its own partition, it is not necessary. You could choose to install to one partition and the installation scripts will sort it all out for you. It is however good practice, as if you ever get a system failure, it allows you to reinstall the system without loosing any data stored in Home.

Nothing however is a substitute for good back up procedures.

Back to installing the operating system.

Finally, having selected my preferred set-up, I clicked Done and the next screen appears. In this page I clicked Next to begin the set-up to format the partitions. In my case all partitions were clear of data and formatting was straight forward, but if you are using a previously used main disc then you need to confirm which partitions you want to format, to allow the system to install. It is possible,for example, to select say sda1, as sda3 is say my /home partition. Provided my /home partition is not formatted, all the data on it will remain intact (but note warnings above). The system will simply pick up /home as being a valid partition for the system and allow access to all files on completion of installation.

Click Next again and the format process will commence and there's no going back!

The next screen to appear, is the one you've been waiting for. When you click Next, the installation begins. Follow the installation making appropriate entries where necessary and click Finish at the end.

Having partitioned the hard drive the installation continued automatically to a successful conclusion. The computer was then shut down using the Ubuntu icon for shut down at the top right hand corner of the desktop.

Booting the computer, on switching it on, is achieved in a terminal type window which appears following a motherboard flash screen. In my case a number of items are listed, the first is Ubuntu and the last is Windows 7. If I turn the computer on and leave it Ubuntu loads automatically. To load windows 7, I wait for the terminal page to appear and using the up/down arrow keys I select Windows 7, press the return key and Windows 7 loads. The following Figure shows how my hard drive was finally partitioned.

The above is, I hope, a comprehensive account of the build of my desktop computer and the basics for loading it so that it will automatically boot into Ubuntu and by selection boot into Windows 7. I trust I have not missed anything out and wish you well should you wish to attempt to build your own computer following the above.