How to build your own PC for under £300

There is only a narrow window in life in which it is possible to teach computer skills to one's children or grandchildren, before they begin teaching you.

AMD's Ryzen range of processors are the best value for a DIY PC

But in an age in which gadgets work as soon as you take them out of the box and switch them on, fewer users are finding it necessary to learn at all. They will know how to share a picture on Instagram but not on to a hard disk, or, for that matter, what a hard disk even is.

The best way of getting your head around what a PC is and does is to build one yourself, whether as an educational project or simply to save money on your own next machine. Even in today’s world of gadgets-as-fashion-accessories, desktop PCs remain tin boxes stuffed with bits and pieces made by different manufacturers. If you choose to splash out on a branded model, it will still be full of other people’s parts.

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At first glance, the prospect of building a computer from scratch may seem off-putting, but many dealers and websites cater for doing exactly that, and offer corner-cutting solutions that can reduce the whole process to just half a dozen parts. The only trick is to make sure each one is compatible with the others, and your dealer should warn you if not.

Here are the basic components:

The box itself: Around £25 will buy you a metal case with a built-in power supply unit, into which you place everything else. They come in hundreds of designs and in upright or box-like designs. The size you choose will determine the sort of mainboard (also called a motherboard) that fits into it. The case will come with the necessary cables but you will need a separate cooling fan if one isn’t included.

Processor, mainboard and memory: This combination is at the heart of any computer, and although the three elements can be bought separately, you will save time and a headache if you let your supplier assemble and test them first. That way, you don’t have to get involved with the layer of thermal paste that sits between the processor and the mainboard, or worry about which of the hundreds of types of available memory is the right one.

Your choice of processor will determine the type of mainboard you need. All of Intel’s chips can be bought as kits but the best value by far is currently in the Ryzen range by the rival manufacturer, AMD. Around £220 will buy you a decent, entry-level Ryzen 3 mounted on a suitable mainboard with an ample 8gb of memory.

Hard disk: This is the unit that stores the files and documents you create. The only real consideration is size, and a standard one terabyte unit is around £35.

Graphics card: Unless you plan to play a lot of games, you don’t need a separate one of these, as the processor itself will have graphics capabilities. But if you do want one, they start at less than £35.

Operating system: I make the price so far £315 or less, which makes the £84 retail price of Windows 10 seem like extremely poor value. However, if you’ve bought a copy already you may be able to transfer the licence to your new machine – and Windows is in any case far from the only option.

All that’s left is to connect the parts together, which takes less than an hour. The internet is awash with guidance on this – but if all else fails, you can always revert to Plan A and ask the teenagers in your family.