Internet.

Q, Since I got a new broadband Internet connection, I stay online all the time and find it very convenient. But my information technology adviser tells me that leaving my Internet access open full-time makes me vulnerable to hackers. Should I assume he's just paranoid about the danger?

A. No, he's correct, but he didn't tell you the whole story. It's not the broadband connection that increases your risk, it's because you've extended the time you're online, and a hacker has more opportunity to get into your system, where he or she can access personal information stored on your computer and even steal your identity.

Does that mean you should limit how long you remain online? No, but you should be aware of the dangers and install a firewall, which is software designed to block the uninvited from entering your computer through your Internet connection.

Understand, however, there are no foolproof security measures; hackers have cracked some of the most secure Web sites--the U.S. Defense Department's and the FBI's, for example. Most people don't need the most effective firewalls--which are expensive and hard to install and operate--because expert hackers generally target only sites where they can steal very valuable data of money of cause mayhem as a political statement.

As a practical matter, you want to guard against the less-than-expert hacker (the one after your credit card numbers), and inexpensive and easy-to-use protection with a low-cost firewall works well. I've used Zone Alarm for some time; a free version can be downloaded from www.zonelabs.com, or you can buy a more sophisticated version of the soft ware for a modest price.

There are many firewalls on the market. To find them, go to a search engine such as Google (www.google.com) and type in firewall.

When it comes to virus protection (hackers can send viruses to you), you should avoid bargain-basement products. The major virus protection software products are McAfee (www.mcafee.com), Norton (www.symantec.com) and Kaspersky (www.kaapersky.com). But again, there are many others, and you can find them via a search engine.

Caveat: Don't delude yourself into thinking once you buy a virus protection program you're sale. New viruses are created daily, and unless you subscribe for regular updates, you're vulnerable to infection.