Spyware. The very word makes me shudder. At home, Web sites can relay details of your PC habits and Internet escapades to who-knows-who. At work, software can record everything you type and report to your boss on which programs you use, as well as when and how you use them.

Feeling paranoid? Well, even if you aren't concerned about a snoopy spouse or a meddling manager, you need to know how these programs work and how to defeat them, if only to spot potential threats to your privacy. I've donned my trench coat and dark glasses to tell you about a few of the tools and strategies I use to watch (and foil) the watchers.

Adware programs, such as GoZilla, are freeware utilities that display banner ads to generate revenue. GoZilla manages your file downloads, but it also uses a small applet that interacts with the company's servers behind your back. The applet sends you new ads, and it tracks the ads you've seen, clicked, and viewed. While the data collected is anonymous, you wouldn't know it unless you read the vendor's 2500-word privacy policy.

One cure is LavaSoft's AdAware, a free tool that scans your hard drive and removes these hidden applets. Visit our list of October's downloads for a download of AdAware, as well as full or trial versions of other utilities I describe here.

ZoneAlarm, a freeware firewall from Zone Labs, alerts me when any program attempts to send or receive data, and it allows me to block or approve each attempt. For an intricate, real-time view of what the programs are transmitting--and who's sending and receiving the data--I rely on Tamosoft's $99 CommView.

Keystroke-recording programs are also spyware. An ad for SpectorSoft's $70 EBlaster 2 says it "automatically records everything your spouse, kids, employees, and consultants do online"--in secret, of course. EBlaster will send a snoop e-mail reports of all your Internet activity, including chat room conversations, instant messages, e-mail, and Web site visits.

If your employees spend half their workdays surfing the Web and e-mailing jokes to their friends, spyware may be justifiable. But I'm not on anybody's payroll, so I'm going to pass along a few tricks to help you determine whether snoopware is on your PC.

First, for a quick check on just what is running on your computer, press Ctrl-Alt-Delete simultaneously. A dialog box will list all currently running programs. Look for programs that contain suspicious or unfamiliar names. For help deciphering these names, see the November 2000 Answer Line, "Identify Mystery Apps Running in the Shadows."

Want to stop something from loading when your PC boots? In Windows 98 and Me, select Start, Run, type msconfig, press Enter, and choose the Startup tab to see a list of the programs that start when Windows loads. Uncheck any that seem to be spyware. Windows 95 and Windows 2000 lack the Msconfig utility, so use Startup Control Panel, a freeware utility, instead.

Kissco's $20 Invisible Folders is a no-nonsense tool that hides folders from snoopware and from prying eyes, either when you press a hot-key or automatically after a set time. Panicware's Don't Panic 4, also $20, clears nearly all traces of your PC activity, including drop-down URL history listings, the Clipboard, and IE's AutoComplete and passwords.

I would tell you more, but it's tough to type in this trench coat. I'll cover spyware blockers in more detail in a future Home Office newsletter, so sign up soon.