Do regular backups

Use USB disks, writable DVDs, thumb drives, online, and/or other computers in your house – photos especially

Anti-virus (MOST IMPORTANT - I consider it negligent to be on the Internet without an up-to-date anti-virus tool running on your computer)

Have a subscription to get regular updates

Have auto-update turned on

Do weekly full-system scans (3AM is a good time)

Firewall

Use built-in firewall (enable in control panel) – or the firewall from your AV

Software Update

For Windows, Microsoft Update keeps the operating system and Microsoft Office up to date

Set to automatically update the system

Run it manually every month or so and select “Custom” and get non-critical updates

Anti-spyware, phishing, etc.

Most AV tools have all these features – spyware is important, phishing, spam, their backup less so

Consider using “Spybot search and destroy” periodically (www.safer-networking.org)

Keep other software up to date

Adobe Reader, Flash, and Shockware (www.adobe.com)

Java (www.sun.com)

Clean out your temp files and defragment your disk every 6 months

Consider parental control software

You are looking to keep logs, limit sites, set time limits (quantity and time-of-day)