6 June 2001

Some people tell me I should shut down my computer at night, others say you shouldn't. Who is right?

There are two schools of thought on whether to turn off your computer when finished. Turning computers off and on shortens their lives, just like a light bulb. Leaving your computer on makes it vulnerable to storms and power surges.

Power surges, blackouts and storms are a fact of life and computers hate them. Probably the most common single cause of computer equipment failing is power problems. Having your computer permanently on means you will almost certainly have to replace a part due to a power surge over the life of the computer.

The other argument is that many older computer parts fail due to fatigue. Each time you turn a computer on it heats up and the parts expand, when you turn it off the parts cool and contract. Over time this expansion and contraction causes parts to fail. Each time you turn your computer on or off is one more time closer to your computer breaking down.

On balance it is best to turn computers off when you aren't using them. Power surges are a certainty and when they strike a computer can be badly damaged. Windows also likes to be shut down regularly, left running without a rest, Windows computers can start behaving very strangely.

Some computers have to be left on if they are servers or working as fax or voice mail machines. It is important that these machines have good surge protection. If you see or hear a storm coming it is worthwhile turning all computers off, regardless of how important they are. Remember that modern computers are still "on" even when they appear to be "off", so disconnect the power and phone lines from the computer before a storm hits.