Reader Ben Madison writes: With the major push to conserve energy in the house these days, I am looking for a program to automatically shut down the computers in the house at a certain time of the night. I work the graveyard and when I leave the wife is usually still up, so shutting down then is unpractical. I've found a few software apps out there for this purpose but was wondering if you've had any experience with any, and what is the best buy for the money. Some are $30+ which seems a little steep for something as simple as setting a shutdown time. I just need something that allows different settings for each day. Any ideas? Thanks in advance.

What a great suggestion, Ben. Computers (especially older ones) are notorious energy hogs. Shutting them down when not in use is an easy, painless way to save cash.

There are countless programs to make it easy to specify a time to shut down your PC every night, but they vary widely in capabilities. But you may not know that you don't need any software at all to automate many PC tasks, including routine shutdowns. The key is the Windows Task Scheduler, which is included as part of XP by default. It isn't brainlessly simple to use like many third-party utilities, but it's free and it will let you set shutdown times for weekdays vs. weekends. Microsoft has a tutorial on how to use it here.

It's pretty self-explanatory, but the trick is to click the Browse button when you are asked for the program you want to automate and browse to the "Windows/system32/shutdown.exe" program. To set up separate times for each day of the week, simply choose the first start date for, say, the next Monday, then select it to perform every 7 days. Repeat for the other six days of the week, and you're finished.

If you're not comfortable with the Task Scheduler, you can certainly try third-party apps. Alas, I haven't found a free one that will let you schedule shutdowns based on the day of the week. The best I could find: PC Auto Shutdown at $20.

If your needs are less stringent, Slawdog Smart Shutdown (pictured) is free and lets you schedule shutdowns and other activities for any time of the day. However, it doesn't let you change that time based on the day of the week.

Remember that schedulers are powerful tools that don't leave a lot of room for error. If you leave programs or (especially) unsaved files open at night, a scheduled shutdown could wipe out work when you aren't expecting it. Tread with caution.

Hope this helps!