While it's possible to bag yourself a bargain by building your own PC, most users - and particularly those new to the world of computing - prefer to buy a ready-made system. If you're looking to pick one of these up, then there's good news: the lightning-quick progress of PC technology means that you can get very respectable hardware for a fraction of what the same gear might have cost just a few years ago.

Getting the best deal for your money still requires a little bit of research, and that's where ITReviews comes in, guiding you through the decisions you'll need to make.

Knowing what you want
As with any purchasing decision, the first thing to do is to figure out your requirements. Will you be playing games, or is your PC mainly going to be a work machine? Do you do any digital photography or video editing that might require more than average storage? Do you need a monitor with it, or are you re-using an older display?

Wherever you go to buy your system, always remember your key requirements. Don't be swayed by the siren song of the bundle: it might seem like a bargain to get a PC that comes with multifunction printer and 'hundreds of pounds' worth of software thrown in for free, but you may just regret it. Bundles are the industry's way of getting rid of stock that it can't sell any other way - and the chances are you'll soon find yourself replacing the hardware and software you got 'free' in favour of more capable accessories.

That said, you'll need to ensure you put enough money aside for the extras when working out your budget. If you're handy with a screwdriver - or have a techie friend - don't be afraid to look at a cheaper system let down by a single weak component, as many warranties aren't affected by changing simple things like upgrading the memory or adding a dedicated graphics card.

As with our other buyers' guides, we'll take a look at three main buying categories to help you figure out what kind of system you need to buy: budget, mainstream, and premium.

BUDGET
As a user on a budget, you want a system that's as cheap as possible without sacrificing usability. You don't care much for gaming, but if the PC is too slow you'll get frustrated and wish you'd spent that little bit more.

Playing games is one of the activities that gives your PC the most rigorous performance workout - and at the budget level, any system you buy is likely to come up a little short when faced with this task. While some might be salvageable by adding in a new graphics card, you can expect to the experience to be awkward and fiddly.

Small form factor
With that said, there's no reason why buying on a budget means that you can't get a respectable system for everyday use. The launch of the Intel Atom processor, designed for compact PC systems and portable 'netbooks', has led to a surge in low-cost low-power devices that offer a remarkably comprehensive list of features, such as the Acer Aspire Revo and Zotac ZBox ranges or the NT-535 from Foxconn.

Compact PC: Zotac's Zbox HD-ND22

What such tiny, low-costs systems lack, however, is upgradeability. With no room for extra hardware, what you buy is what you get. Worse, most don't include optical drives such as CD writers, DVD or Blu-ray drives - so you'd better budget for an external USB device, as you'll almost certainly need to install software from a CD or DVD at some point.

Full-size desktop PCs
If you don't particularly need the savings on space offered by Atom-based systems, full-size PCs featuring older Intel Pentium or AMD Athlon II chips are often available for much the same price. If you want to get your hands on systems that use Intel's latest Core i3 range of chips, however, you can expect the price to rise considerably - putting the latest technology out of reach of the budget buyer and firmly in the mainstream category.

Memory (RAM)
Don't consider a system with less than 2 gigabytes (GB) of system memory, also known as RAM. The usual type of RAM seen on desktop PCs these days is known as DDR3, and comes in a range of speeds, generally from 1066 megahertz (MHz) upwards. For preference look towards 3GB or more. While Windows 7, provided with the majority of PCs on the market at the current time, requires significantly less memory than the previous version, Windows Vista, 2GB is the bare minimum if you're looking for an enjoyable computing experience.

Storage - hard disk and optical drives
Systems in the budget price range usually come with a 250GB hard drive, which should be enough for even the most avid digital photographer. Better yet, almost all systems - with the exception of the small form factor Atom boxes mentioned above - also include a DVD rewriter (DVD-RW) drive, allowing you to read and write to DVDs and CDs at no additional cost.

Display
If you're buying in a bundle - and we really advise you don't - you can expect to get a 17in or 19in flat-panel TFT monitor, but be prepared for slow refresh rates and a slightly blurrier image than you could get buying the display separately. Look out for digital DVI and HDMI connection, rather than the older analogue VGA.

For a system in the Budget price range, expect to pay between £250 and £350, plus another £70 to £100 for a suitable monitor.

Tags: hard disk bundle buyer's guide nvidia amd graphics card intel desktop pc