How to build your own PC

Since its launch five years ago, Computeractive has striven to demystify computers and make you more confident about using them. Judging from the letters we receive asking for ever-more technical content, we seem to be succeeding.

If by now you're comfortable taking the lid off your computer to upgrade it, you are almost certainly ready to take the next logical step: building your own computer.

This isn't as daunting as it sounds and the most complicated part of the job is choosing the components to go in it. To keep things simple, we have done this for you and we've kept the price down to around £320.

Of course there's nothing to stop you spending more and picking your own components. You'll still be able to follow our step-by-step guide with barely any changes.

Getting started
Building a PC to any budget means making some decisions and one of the first is which case to use. For the purposes of our PC, we have opted for the cheapest we could find.

We found a standard case with power supply for £30 at our local branch of Maplin Electronics. It's not particularly handsome but there are far uglier cases being used by big-name PC manufacturers.

Any case that can accommodate an ATX motherboard and has a 300W power supply will suffice; it's up to you how much money you spend.

One of the most important computer components is the motherboard and this is where things start to get complicated.

There are literally hundreds of different motherboards available and picking one depends on which processor you intend to use, what features you need and even what colour you want.

For simplicity's sake, we have chosen a completely integrated motherboard - one with almost all of the features you would ever want built in.

In days gone by, integrated motherboards were frowned upon, as they were saddled with middling performance, awful graphics and weak sound. Not any more. The £90 MSI K7N2G motherboard we're using is based around nVidia's nForce 2 components and has good performance, good 3D graphics and great sound.

As you'll see when we start building, it also has a list of built-in features as long as your arm.

Our choice of an nVidia motherboard limits our processor to one made by AMD. This is actually a good thing, since AMD processors are much cheaper than those made by Intel.

To keep the price down, we're using an AMD Athlon XP1800+ processor, which costs £52 from Dabs.com, the cheapest supplier we found at time of writing.

Next on the list is memory and the 256MB we're using is the bare minimum for any new PC. One quirk of the nForce 2 motherboard is that it gives better performance with two sticks of memory rather than one.

With this in mind, we bought ourselves two 128Mb sticks of memory. These cost a couple of pennies shy of £40 from Crucial.com and will still leave us with a free slot for future upgrades.

For the hard disk, we picked a 60GB model and there was little to choose between PC NextDay and Dabs.com on price. We could have gone for a smaller drive but the price difference between a 40GB and 60GB version is less than £10 in many cases.

While there is no problem having too much spare hard disk space, there is certainly no joy in having too little.

Keyboard, mouse, modem, floppy disk and CD-ROM drives can be sourced as cheaply as possible if your budget is super-strict. We tried PC NextDay, Dabs.com and Maplin but the convenience of shopping in one place will probably be the motivating factor.

If your old computer is going to the dump, all these items could be salvaged from it and used in your new one. (For more ideas on what to do with your old PC, see our feature here.) If your budget is very tight, the odd pound saved here could allow for a faster processor or more memory.

Before you begin building your new PC, it's important to ensure that you don't damage any of its components with careless handling. Building it in a room with carpet on the floor is asking for trouble with static electricity.

An anti-static wrist-strap is one solution; working in a room with a hard floor is another but a combination of both options is best.

It's also better to work in a room with a table where you can leave your half-assembled PC undisturbed; the last thing you want to do is sweep the bits off the kitchen table so that you can eat your dinner.

HOW TO BUILD A PC IN 18 EASY STEPS

STEP 1: Once you have ensured that you have all the parts you need to get building, you can begin preparing things. The first step is to secure your anti-static wrist-strap.

We strongly advise you to invest in one of these as static electricity will wreck delicate electrical components, such as the motherboard and memory. Affix the strap according to the instructions and ensure the work surface is clean and dry.

STEP 2: The first step of the building process is to disassemble the case ready to install the motherboard. With our case, this means removing both side covers.

Inside is a small cardboard box that contains an assortment of screws and fixings. Remove the box from the case and leave it to one side for the time being.

Put the side covers out of the way as they won't be needed again until you complete the construction. With the side covers off the case, you can see the likely positions for the CD-ROM and floppy disk drives.

Next, the blanking panels in the front of the case must be removed. This requires care. The plastic panels at the front are relatively easy in the majority of cases - they can be popped in and out.

Press the centre of each plate firmly. They will bend and eventually pop out. Once one is removed, the rest can be pulled forward. Remove all the blanking plates so you have good access to the metal blanking plates behind.

The blanking plates for covering unused PCI slots should be opened up in the same way, leaving all the expansion slots open.

STEP 3: The metal blanking plates often have very sharp edges and are sometimes quite hard to extract. As a degree of force can sometimes be necessary, we have chosen to remove the plates now rather than when the motherboard is installed.

Often, the plates are held in place with small spot-welds and the only way to remove them is to insert a large, flat-bladed screwdriver into one of the blanking plates and lever them away from the rest of the case.

Once all the blanking plates are removed, throw them away. Be very careful of the case edges as they can be very sharp. If you are in danger of damaging yourself on the edges, put a strip of insulating tape over them.

STEP 4: The next thing we need to do is fit the motherboard. As the PC case is designed for lots of different motherboards, the fixings are not in place. The fixings are called 'standoffs' and are usually made of brass.

We need to look at the motherboard to see where the fixings are positioned so we know where to fit them in the case. The easiest way to do this is to trace an outline of the motherboard on a piece of paper or card.

Use a pen to mark where the mounting holes are. With this done you should have a template of your motherboard. Punch the mounting hole markings out of the template and cut around the traced outline of the motherboard.

Place the template inside the case - there should be holes in the case where the mounting holes on the template fall. Screw a standoff loosely into each mounting hole, rip out the paper and then screw in the standoffs to finger tightness.

STEP 5: With the standoffs in place, the next task is to install the motherboard into the case. Before putting it in, the blanking plate for the ports that poke from the back of the case must be fitted.

If one comes with the case, discard it - we need the one that is supplied with the motherboard. The plate needs to be pressed into place from the inside of the case. Ensure that all the edges are located correctly and that it is straight.

STEP 6: We are now going to put the motherboard into the case. This requires great care. With the ports and plugs facing the back of the case (where you just fitted the blanking plate, in other words), slowly lower the board into it.

As the sockets are pressed into the template, ensure that everything is lined up properly and that there are no tabs obscuring any of the plugs.

When all the standoffs are correctly aligned with the motherboard mounting holes, use the screws supplied with the case to fix the motherboard in position. Put one screw in each mounting but don't tighten them fully just yet.

Once you are sure that all the sockets poke through the holes in the blanking plate properly, tighten the screws. Again, they should be firmly screwed but do not tighten them too much as you may damage the fixing or the motherboard.

STEP 7: With the motherboard in place, we can now begin fitting the other components. The main ones are the hard disk, floppy drive and CD-ROM drive. The hard disk and floppy disk positions are usually pretty self-explanatory.

The floppy drive has to be accessed through the front of the case and there will only be a choice of one or two suitable 3.5in drive bays. Place the floppy drive in the bay and look at the power supply and IDE ribbon cables to ensure they can reach the drive without stretching or obscuring key components, such as the memory or PCI slots.

Do the same for the hard disk and CD-ROM drive. With these, also ensure that the drives themselves will not obscure important parts of the motherboard.

If there is plenty of room in your case, you can fit the drives now. If space is a bit tight, make a note of your chosen positions for each drive before removing them and placing them to one side.

Before screwing in the hard disk and the CD-ROM drive, check that the jumpers on the back of each are set to 'master' (not 'slave'). Instructions on how to do this will normally be marked on the drive itself.

STEP 8: The next important job is to connect the motherboard to the front panel connectors on the case - this is one of the most fiddly tasks. Somewhere in the case will be a bundle of wires with tiny black plugs on the end. Each plug will be labelled. These are for connecting the power and reset switches, case speaker and so on.

Every motherboard will be slightly different so it is important to read the manual that comes with it. If your computer won't switch on when you first turn it on, these connections are worth checking before anything else.

STEP 9: Check the heatsink for your processor. If the base (usually made of copper) has a small grey pad stuck to it, skip this step. If not, you'll need to apply some thermal grease to it and the processor.

Thermal grease smooths out any microscopic imperfections on the heatsink base and processor, ensuring a snug fit that helps the heatsink to do its job.

Apply a pea-sized blob of grease to the heatsink base and, using a thin strip of card, carefully apply a thin layer to the processor.

Only apply grease to the raised area in the middle of the processor. Then, smooth the remaining grease over the base of the heatsink.

STEP 10: The next step is to install the processor. First, find the socket for the processor. Along one side, you'll see a brown lever. Carefully unhook the lever from the small lip at the side of the socket and lift the lever to point upwards.

Now get the processor. Look at the bottom of the AMD Athlon processor and you will see that the pins are arranged around the edge of the chip with two corners missing pins. The processor slot also has two flattened corners - the processor will only fit one way round.

The processor should drop neatly into place but it may require a gentle tap on one side to ensure that every pin is in a hole in the socket.

If not, check that the socket level is fully lifted and that the processor is the right way round. When the processor is in place, lower the lever and snap it in place.

STEP 11: Fitting the heatsink and fan unit can be very tricky and great care must be taken to avoid damaging the motherboard or the processor. Heatsinks come in many different shapes and sizes but it is important to get it the right way around in order that it can do its job correctly.

The processor socket has one raised edge which has 'Socket 462' written on it. One side of the heatsink will have a raised or stepped edge to accommodate this. Ensure that the stepped edge lines up with the raised edge and that the spring clip in the centre of the heatsink lines up with the lugs on the plastic processor holder.

Once you are sure that everything lines up correctly, look at the spring clip. One end has a small lip for a flat-bladed screwdriver. Hook the other end over the lug on the opposite side of the processor socket and then insert the screwdriver into the lip.

Press the clip down and lever it gently over its lug using the screwdriver. Some clips can be extremely tight and you'll need to take great care not to exert too much pressure in case you damage the processor. Locate the nearest socket on the motherboard for getting power to the fan. There are usually two or three of these on the motherboard.

STEP 12: Connecting the disk drives, motherboard and power supply together is the next job on our list. The motherboard we have chosen has three IDE sockets. These are marked as IDE1, IDE2 and IDE3.

The hard disk needs to be connected to IDE1 using the wider of the two grey ribbon cables supplied with the motherboard. The blue end of the ribbon cable should be plugged into IDE1 and the black end into the hard disk.

A flat grey IDE cable should also have been supplied with your CD-ROM drive. This plugs into the IDE2 socket and then into the CD-ROM.

If you are fitting a floppy drive, a thinner grey cable was supplied with the motherboard. This plugs into the socket marked FDD1 (floppy disk drive) and into the floppy drive at the other end.

STEP 13: There are several bundles of wires coming from the power supply. The largest of these will have a large rectangular plug on the end and this connects directly to a large white socket on the motherboard. It will only connect one way round.

There should also be a smaller square white plug which, on our motherboard, connects to a small white socket near the large one. These plugs provide the power to the motherboard.

The rest of the connections will be a mixture of four-pinned plugs about 2.5cm wide and a couple of much slimmer ones just over 1cm wide.

Connect one of the larger ones to the CD-ROM drive and one to the hard disk. One of the smaller ones will hook onto the back of the floppy drive. All of these plugs will only fit one way around.

STEP 14: Fitting memory is one of the simplest tasks there is. Our motherboard requires two sticks of memory to give its best performance and the slots are colour-coded to show where to put them. In our case, that means one stick of memory in the green slot and one stick in one of the purple ones.

In most motherboards, the memory can be fitted in any of the available slots. If your handbook says to fit it in particular slots first, follow those instructions. The slots are numbered on the motherboard. Ours were called DIMM1, DIMM2 and DIMM3.

STEP 15: The only PCI card we are fitting is a modem. When the PC is as bare as this one, finding space is very simple. With the metal blanking plates at the back of the case removed, simply press the card firmly into a vacant slot.

When the bracket at the end of the card is resting on the case, use one of the supplied screws to secure it. Before tightening it, ensure that the modem plugs are free of obstruction and that the phone line plugs can be connected and removed easily.

STEP 16: Most motherboards have extra USB or FireWire ports which plug straight into the motherboard and occupy one of the expansion slots at the back of the PC without actually using a PCI slot. Our motherboard has both, as well as two sets of supplementary connections for the on-board sound and video.

Use the motherboard handbook to find the place where these extras plug into the motherboard. All the plugs on all four of our extra devices were designed so that they would only plug in one way around.

Any unused openings at the back of the case should be obscured with a screw-fixed blanking plate. This will help to stop your PC sucking in too much dust when it is used.

STEP 17: With everything connected, we are ready to screw the sides back onto the case. Just take a minute to check everything is connected and firmly screwed into place.

Replace the plastic blanking plates into any unused drive bays in the front of the case. Finally, screw the side panels back onto the case. Well done. You have built a PC.

STEP 18: When you turn on your new PC for the first time, you will need to enter the BIOS set-up screen. The motherboard we have chosen automatically sets up the memory speeds and the processor and finds our disk drives so the amount of setting up needed is minimal.

What you will need to do is ensure that your computer is set to boot from a CD-ROM. The ComputeractiveWorkshops in issues 108-111 cover installing Windows from scratch. These Workshops can be downloaded for 25p each from www.computeractive.co.uk. That's it - enjoy your PC.