Inevitably at some stage the primary source of power to your computer will be cut – and if you are in the middle of something important you can be sure there will be data loss or corruption.That is why you need a UPS. Not the postal service kind – the one that keeps your precious digital noughts and ones flowing when the power keeping them in sequence is interrupted.[This is aimed at those who use a desktop computer and/or data switches/hubs/routers/modems that don’t have their own internal power source]An Uninterruptible Power Supply (UPS) is a simple box that provides a short-term backup power supply if and when your primary source is stopped – like a power cut, blackout or someone tripping over a power cord (if you solely use a laptop you’ll be grateful of the internal battery when you have experienced power outages and/or the advantages of being able to move to a new outlet without losing any time/function while you change over).In the event mains power is removed it switches instantly to a battery powered mains inverter to provide seamless continuity of power.The words ‘if’ and ‘when’ are pointers to it not being if but when it does happen. Without backup power protection everything stops, dead. At some time you will have experienced it. Hopefully the consequences were minor. You may have been lucky enough to be able to carry on where you left off, once the power was restored.With a UPS in-line between your computer and the power source you’ll have one of two outcomes:Power will be returned without you needing to take any action and you’ll carry on like nothing ever happened.You will have plenty of time to finish what you are doing, close essential files and shut down your computer before the battery supply inside the UPS is exhausted (typically 20-30 minutes).That leads to the next question: what size and type should I get?They come in so many shapes and sizes – to suit all purposes and scenarios, and that’s where confusion regarding having a UPS leads to making a protracted decision. Same goes when it comes to cost.Here is a base scenario:Desktop PC of moderate configuration (say a hundred watts power consumption), add monitors, and other small power consumption devices and it would be over estimated at 300W. Double that = 600W – that’s what you should be looking to have – to cover the additional power demands when you’re doing start-up/shutdown and consumption spikes momentarily.Double your estimated power consumption = the device you can be sure will do the job.One pre-warning, remove any laser printers, scanners, heaters, lighting or non-computer type devices – aside from non-essential some of them either consume a lot more power or don’t like the modified (non-sinusoidal waveform) style of alternating current supply.A good 720W (1200VA) UPS should ring in around the NZ$200 mark – and generally includes batteries (so it’s ready to go).A pretty darn cheap way of being sure your data stays in check regardless of what happens to your primary supply. The risk of data corruption when power is suddenly removed is pretty certain – so what price would you put on having a level of assurance you aren’t going to suffer at the hand of random fate?Have a UPS between your computer (and its necessary peripherals). Now!