Q: Before I sell or donate my old PC, what should I do to remove personal information?
A: This is a great question. When you "delete" data from a hard drive, the information actually remains magnetically encoded in the drive until it's copied over. That data can be recovered unless the sector of the disk it's been written on has been copied over several times.
Now, for most people, this isn't a big deal. But if there's stuff about you on your hard drive that you'd prefer nobody know about--you've got a disease, you used to be a Republican senator, you're a journalist--you'll want to take steps to make sure that information is gone before passing that computer and its hard drive on to strangers.
You'll want to get an information "scrubber" program, which will repeatedly record data throughout the drive, making data recovery difficult, if not impossible. There are plenty out there, and we can't offer any recommendations. If you want to be extra careful, yank out the hard drive and smash it open before disposing of it properly. Plenty of people will happily buy a used PC without a hard drive, and some charities will accept them too.
You think we're paranoid? The last time we looked at the Navy spec on this--which admittedly was some time ago--it called for, among other things, soaking the drive in acid for three days before disposal.
Q: I have the Microsoft Office shortcut bar on my desktop. I have chosen which programs and files to be shown on it. The trouble is when I open various files, they then appear in the shortcut bar, which gets filled with unnecessary files. How do I prevent this?
A: Quick and dirty fix: Throw out the shortcut file you've been using and create a new one.
Q: I have Windows on my home and office computers. Every once in a while, I hear the sound similar to a door opening. I hear it on both computers. What is that sound, and does it spell any upcoming problems?
A: The friendly geeks at Q&A; labs believe you have some kind of instant-messaging system running in the background on both machines. We know you don't believe us, but it's true. That sound is traditionally used to let the user know when somebody on the buddy list comes and goes offline.
Dave Wilson is The Times' personal technology columnist. Submit questions to Tech Q&A; at email@example.com.