1. Use anti-virus software and keep its virus definitions updated

For personally-owned PCs, students can download Symantec AntiVirus for free at https://intraweb.usfca.edu/its/usfpublic/norton/index.html.

To manually update your virus definitions:

1. Open Symantec AntiVirus by double-clicking on its icon (a yellow shield) in the task tray at the bottom-right of your screen.

2. Click on LiveUpdate and follow the instructions. Note the version number and date may not update immediately. The first time you try to update the virus definitions, the update will fail. You must run it a second time.

Or, you may choose to use another anti-virus software program. Students living in residence halls subject to network access control should choose a supported program - see the complete list here (about halfway down the page).

Anti-virus programs can conflict with each other and may cause your PC to slow down. If you experience problems running more than one, you should disable or uninstall others.

2. Keep your OS updated with the latest patches

Windows - click here for instructions to set your PC to update automatically (must be running Internet Explorer 5.0 or later and have administrator rights).

If you do not have Internet Explorer 5.0 or later installed, click on Start, Control Panel, Security Center and Automatic Updates (under "Manage Security Settings for:"). Choose "Automatic".

Mac - TK - this whole section - have no info yet
Overview of Mac OS X security features - www.apple.com/macosx/features/security.
SecureMac
MacInTouch

3. Use a firewall

Windows

Make sure your Windows firewall is turned on:

1. Click on Start, Control Panel, Security Center, Windows Firewall.
2. On the General tab, check whether the Windows firewall is on.

Alternatively, instead of using the Windows firewall, try the free edition of ZoneAlarm, from Check Point Software Technologies. The company also offers other products (see comparison chart).

Mac

1. Open System Properties.
2. Click on the Sharing icon.
3. Click on the Firewall tab.
4. Click Start if the firewall is not already on.

4. Keep other software updated with the latest updates/patches

5. Use anti-adware/spyware software

Ad-aware SE Personal, from Lavasoft, free, search for it on CNET Networks' Download.com. The company also offers other products (see comparison chart).

Spybot - Search and Destroy, free.

AVG Anti-Spyware, from Grisoft, free 30-day trial. Can continue using basic features after the trial has expired.

SpySweeper, from WebRoot, $29.95.