My buddy, a network administrator, insists on leaving his PC on day and night. He says that the system's RAM, CPU, and hard drive can be harmed by turning the system on and off.

I agree that treating the computer like a microwave and flipping the switch a dozen times a day could cause problems. But turning it on in the morning and off at night? Not a big deal.

Either way, it's still a controversy. But I'll tell you what I do: I turn it off at night. With two monitor and three hard drives, I burn up energy even with power saving settings.

For more on saving energy, read Microsoft's article, "Do you need to turn off your PC at night?"

Dig This: Need another reason to turn off your computer? I'll bet you don't have any idea what happens on your desktop in the middle of the night. Watch this actual video screen capture to learn the shocking truth.

Free Tool to Save Energy

I'm experimenting with UniBlue's free Local Cooling program. The downloadable software gives you an easy way to control the power consumption of a PC. Once loaded, you can set the tool to switch off the monitor, spin down the hard drives, and hibernate to PC after a specific time.

What's cool is seeing the amount of energy you're saving. After a short while, I've saved 0.139 trees (a redwood, I hope), 1.265 gallons of gas (probably unleaded), and 2.63 Kwh of power. The site claims over 11,000 users have joined, and I'm one of them.

Granted, the power saving estimates are just that--estimates. But it keeps my attention focused on saving energy and possibly helps to decrease global warming.

Dig This: What's that bug, you ask? The one that's uglier than ugly, and scary to boot? Send a picture to the nifty Whats That Bug site and get an expert to identify it. Before you send an image, check the existing IDs located on the home page.

Clean and Tidy PCs

You're not going to save much energy by keeping the insides of your PC clean. But you can definitely increase its life span by getting the dust (technically known as schmutz) off the fans and removing crud from the CPU's heat sink fans.

Coincidentally, I just did a column on the topic, craftily entitled "Top Tips for a Cleaner, Faster Computer."

I always run out of space in my print column, so I wasn't able to talk about monitors and keyboards.

De-Schmutz the Keyboard

My keyboard's always catching dust, bread crumbs, and unidentifiable schmutz. To get rid of all this stuff I take it outside and blast it with a can of air. I have an Avant Stellar keyboard and it has four screws on the bottom. I remove the screws, detach the keyboard from the case, and use the air can there, too. You might want to try this if you have the courage--and the handyman skills. I also use a tissue and rubbing alcohol to remove the grime that builds up on the keys.

For more ideas, read Stan Miastkowski's excellent step-by-step, "Keep a Clean Keyboard."

I've never done it, but some readers recommend that if you spill beer--or any other liquid--on your keyboard, try popping it into the dishwasher.

While I'm talking about keyboards, here's a good site to tuck away if you ever have trouble removing keys from your keyboard.

Clean the Display

For monitors, you can watch the Digital Duo's "Keep Your Screen Clean."

Me? I follow the advice I found on Lenovo's ThinkPad site:

1. To clean, gently wipe the LCD with a dry, lint-free soft cloth.
2. If a stain remains on the LCD, moisten the cloth with water or a 50-50 mixture of isopropyl alcohol and clean water.
3. Wipe the display with the moist cloth; do not let any liquid drip into the computer.
4. Let the LCD dry before closing the lid.

For even more tips, take a look at the "Complete PC Preventive Maintenance Guide."

Steve Bass writes PC World's monthly "Hassle-Free PC" column and is the author of PC Annoyances, 2nd Edition: How to Fix the Most Annoying Things About Your Personal Computer, available from O'Reilly. He also writes PC World's daily Tips & Tweaks blog. Sign up to have Steve's newsletter e-mailed to you each week. Comments or questions? Send Steve e-mail.