1. Install a good anti-virus program and make sure that it is updated regularly. While most of today's programs update automatically, you should check occasionally to make sure they are working properly.
2.  Don't open email attachments even if they are from someone you know. Open only if you are expecting them, you know the person sending them, and you know what the attachments contain.
3. Don't fall for phishing schemes or other email where they try to get you to confirm or retype your personal information.
4. Update your operating system regularly. In Windows and Mac OS X you can turn on automatic updates, but you also need to download and install the updates as soon as possible. Often the bad guys take advantage of new operating system holes as soon as they are discovered. Companies like Microsoft, Apple, and others find a way to plug the whole and issue an update. If you wait a week or two to install the updates, you are giving the hackers and spammers time to attack your computer.
5. Be careful about the websites you visit. Don't visit porn sites or other suspicious websites. Don't download software from any website unless you are sure it is safe.
6. Use a firewall. As I stated in a previous column, a hardware router is a very good unobtrusive firewall. If you don't have a router, turn on the firewall that comes with Windows. The Vista firewall is pretty good, and the XP firewall is better than nothing. If you are an expert user, you can use a software firewall like Zone Alarm, but for the uninitiated user, these complex software  firewalls can be difficult to use.
7. If you are using Vista or Mac OSX, or even Linux you should create an account for daily use that does not have administrative rights. That way, if a piece of malware gets into your system during an average computing session, it will have restricted rights. Using an account with administrative rights, gives the malware administrative rights as well. While this is also a good practice with Windows XP, most users, including myself, find that because of the way XP is engineered, it is almost impossible to perform average tasks unless you are logged on as an administrator. Fortunately, with the Vista operating system, you can easily perform day-to-day operations when logged in as a non-Administrator.
8. Even with good habits, it can be useful to occasionally run a good anti-spyware program to scan and remove spyware from your computer.
9. Shop at Secure Sites. If you shop on the Internet, enter your personal information and credit card number only on a secure Web page. If you use Internet Explorer, a secure site will show a yellow padlock in a closed position on the toolbar at the bottom left-hand side of the screen. Netscape will show a closed darker colored padlock somewhere on the bottom toolbar. In both browsers, a secure site will have https: rather than http: in the Web site address at the top of the page.
10. Don't give your Social Security number out on the Internet. Identity theft is one of the fastest growing crimes because computers and the Internet make stealing an identity from an unsuspecting victim easy. So don't be an unsuspecting victim!  Your social security number is the golden key to your identity.  Never keep your social security number anywhere in your computer. Never give it out over the Internet, even in a secure site. Some sites, like online banking, may require you to use your social security number as a password. Take a pass on any such site or service that makes you send your social security number over the Internet. Keep your identity secure by keeping your social security number as private as possible.

One more thing- don't buy anything from spam or unsolicited email. While this won't keep your computer any safer, it might help to lessen or eliminate spam. If no one bought anything from spam, it would take away the financial incentive to send spam and it would probably disappear.