In what I'm guessing is a response to my post, Turn a PC Off or Leave It On?, Jim Lane asked if he could back up computers when they are not turned on.

No, you can't. You have to back up your computers when they're running. There's really no way around that.

Unfortunately, a lot of backup programs, antivirus programs, and other maintenance tools default to running certain chores in the wee hours of the morning. The idea is that since you won't be up working, you won't be bothered when these chores slow down your PC.

The problem, of course, is that this convention assumes that you leave your PC on 24/7. As I described in the previous article, there's really no good reason to do that, and several reasons not to.

If you are using network- or cloud-based backup, I suggest you set it up to run at a time when your PC is likely to be on, but is generally near the end of your workday. If you're backing up to local media, such as an external hard drive, get in the habit of plugging in the media and starting the backup when you're done for the day. Many backup programs have an option to shut down your PC at the end of the backup, allowing you to start the backup, then walk away.

Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at [email protected], or post them to a community of helpful folks on the PCW Answer Line forum. Follow Lincoln on Twitter, or subscribe to the Answer Line newsletter, e-mailed weekly.