AKA UPS or UPC

Battery backup? Yes, you need it. On every machine including routers, switches. These devices are extremely low cost self maintenance that can reduce the chance of computer woes. Is your present one making weird noises? Throw it out and get a new one (EDIT: or take advantage of the great tip in comment #1 below). Life expectancy is around 18-24 months. If you get more than this then consider it a cyber bonus. Yes, batteries can be purchased, but concerning the typical unit it is ususally more economical to replace the whole unit. BE SURE and DO NOT plug a printer into the actual battery powered backup side. Printing devices pull huge amounts of amperage and can shut the unit down creating a crash. Where do you get them?
That's easy:

WalMart

OfficeMax

Staples

CircuitCity

BestBuy

Just click on one of the above links and choose the device that suits your budget, needs, etc. Don't buy a wimpy power strip. Do buy something that has some weight; that means batteries inside. If you leave your PC unattended for lengths of time be sure and install the software supplied. This will close all programs properly and do a clean shut down. Please please abide my plea. This is so very important. Test them on occasion. How much should you spend? Start somewhere in the 40 bucks range. Now do it!


"To dare is to lose one's footing momentarily. To not dare is to lose oneself."
-Soren Kierkegaard