Safe behind the firewall
The first thing you need to do is choose a personal firewall to make sure would-be criminals can't gain access to your computer. If your PC is already infected, a firewall will stop offending applications from reporting back to the mother ship. A number of commercial options are available, but to safeguard your system immediately, you're going to want a trustworthy free program until you decide which firewall to buy. In fact, some free firewalls provide sufficient protection against attacks, but the paid versions offer more features that might be worth your money.

A couple of great firewall programs fitting this description are ZoneAlarm and Kerio Personal Firewall. These programs let you use a wizard to immediately get started and defend against almost all types of attacks. Both also offer free versions that provide basic protection until you decide whether you want to buy the whole suite of security software.

Software that smacks down spies
Getting a good firewall program is only part of the solution. Next, you'll need to download one or more antispyware apps to check your system for current culprits. You should also start a regimen of checking your computer on a weekly (or daily) basis for new or repeat offenders.

The best antispyware software scans your hard drive for offenders and lets you obliterate them with the click of a button. These apps offer easy-to-use update features, so you can catch the latest forms of adware and spyware as soon as they hit the Internet. Some of these programs also can be used to clear traces of PC activities and Web-surfing history, quite useful if you share your computer. As a bit of added insurance, we recommend using several spyware-removal programs to make sure your system is spic-and-span. We suggest these four reliable antispyware tools, proven to be highly effective in our tests:

• Spybot - Search & Destroy
• Ad-Aware SE Personal Edition
• Webroot Spy Sweeper
• Spyware Doctor

With a good firewall program and one or more spyware-removal tools installed, your home computer should be safe from almost all forms of adware and spyware. Just remember to stay in the habit of regularly scanning your PC, and you'll be rewarded with a system that's nearly bulletproof.