Tom Boyd wrote to ask about security issues in regard to using a wireless network in one's home, saying he has heard that a neighbor could access your computer. Yes, going wireless increases the risk of others being able to get into your network; however, there are many security measures that can be used to protect yourself.

One method is the encryption of sensitive data, such as financial transactions with your bank or an online vendor, most of whom now have reliable protection systems in place. These establishments all have Privacy and Security links on their sites —— usually at the bottom of their home page —— that explain how these systems work. If in doubt, call or write to those with whom you would exchange critical data.

Mary and I do all our banking and most of our shopping online, and never have any problems

Also available for home-based wireless networks are programs that scan your system for potential security leaks. Such a program, Microsoft Baseline Security Analyzer, is freely downloadable from the MS site, or you can find a link on my site.

Also, everyone needs a firewall, whether your PC is wired or wireless. I prefer the free one from ZoneAlarm (which has a link on my site) to the one that comes with Windows SP2, which I disabled. Some users prefer a mechanical firewall, such as the Belkin 4-Port Router, which can be found at any computer store.

For those who connect wirelessly to "hot spots" in hotels, airports and other places, I received an ad today for a $12.95 hand-held device that claims to help find the best location for reliable connectivity in these areas. A link to Serif products is also on my site.

Regarding security, we all need an onboard anti-virus program and one or more anti-spyware programs to clear out the unwanted cookies we pick up when visiting certain Web sites. Beyond that, common sense tells us not to click on pop-ups saying that we are the millionth visitor to a site and have won a valuable prize. Also, clicking on links for "free screen savers" and "free emoticons" —— where you have to give your e-mail address to download the freebies —— is a sure way to get on multiple spam lists.

Even using IMs (instant messages) can make you vulnerable to receiving malware, if you click on a link that someone sends you. An IM used to be considered safe because you are normally corresponding with a friend whom you trust. Now, however, hackers have ways of accessing an IM and making it look as though a link came from your friend. You can't be too careful.

Jan Sperla wrote to say that she can't see pictures or other attachments sent to her via e-mail since installing McAfee AntiVirus. This can be fixed in Outlook Express by going to Tools>Options>Security, where a number of e-mail restrictions can be enabled or disabled. Experiment to see which choices work best for you.

More tips can be found at www.pcdon.com, and calls are welcome at (949) 646-8615.