The answer to this question is in the end left to you, but there are three things to consider when making this decision.

Hardware failure. The parts inside of your system move, moving parts wear, and parts wear out. This however may not be as big a fear as it has been in years past, many will tell you not to worry about it. Hard drives, fans, etc have all improved and last much longer than before. The operating system, OS X or Windows, will often be set to power down moving parts when they are not in use, check your settings to make sure this is happening. Be sure to keep the computer clean inside and out. Systems that fail that are left on all the time often fail due to heat from inadequate ventilation or dust buildup. Dirty power can also cause system failure and lost data. Getting an uninterruptible power supply, or UPS, will help protect the sensitive hardware from blackouts and brownouts, that over time, can cause random problems to creep up by slowly destroying your hardware.

Safety. Your computer may seem very smart, offering to help you write a letter or warning you that you may have a virus, but the computer is only as smart as you make it. Antivirus, antispyware, and firewall software is all there to help protect your computer. Sometimes things get through this protection and you want to be there when it happens. Just as you would not leave children home alone unsupervised, you don’t want to leave your computer turned on and connected to the Internet without supervision. If you have a direct connection to the Internet you may want to turn off the machine or the Internet connection when you are not using it to better protect it from Internet threats.

Energy. Go green. We are hearing this more and more. A typical computer power supply is between 250 and 500 watts. It won’t use all this power all the time, but the power usage is significant even when surfing the web or editing a document. By turning off the system every night instead of leaving it on, you can save not insignificant amounts of power and of course money.

These are just the surface of the question. You can set your system to go to sleep mode or hibernation when you are not using it. You can change various power saving settings in both OS X and Windows to help save power and keep your computer safe. In the end the decision is up to you, but there is one final thing to remember. Be consistent. Over time, connections inside the system may go bad, but not cause immediate problems. A computer that is left on continually for two years, keeping the connections together with heat and electrical contact constantly, may not turn back on after two weeks of being turned off. A system that is powered down every day may not respond well to being left on for two weeks straight either. Make a decision and stick with it.

I welcome your feedback below.

Bryan can be reached at datilus@gmail.com