Each of us should protect our own computer from virus attacks and prevent spreading of malicious malware. The following are some suggestions.
If you want more information on any of this, please contact me, at beaverhawk.mac.com
Install and maintain security protection
Some security systems cost money but may be easier to maintain. Among these are Norton from Symantic www.symantec.com, and McAfee from www.mcafee.com/uk.
Free programs for the Macintosh include iantivirus available from ianti virus
Free programs for Windows machines include AVG and Ad-Aware.
Any of these programs can scan and clean your whole hard disc of any installed Viruses, Trojans, Worms and other forms of Malware.Yes, you need to install and use one of these.
Maintain an up to date operating system.
The current Microsoft system is Windows 7, which costs anywhere from $90 to $200, depending on options. Older systems, including XP are no longer supported by Microsoft, although they may still run.
In all cases, it is important to leave all Microsoft security features on, including automatic updating. Microsoft plugs security problems in its software on a monthly basis.
The current Macintosh system is Mac OS 10.7.3, which requires the newer dual core machines. Older systems are still supported and, again, it is important to leave software update turned on and to accept security updates, although these are much less frequent than on Windows machines.
If you are planning to purchase a new computer, consider the Macintosh which is much safer so far and subject to far fewer security exploits.
Choose a secure browser
Keeping your browser current is important for two reasons:
1. the newer versions are likely to be designed to handle current web pages
2. the newer versions are built with greater security and protection
Explorer

If running a Windows machine, the current browser is Explorer 9, which is the first Explorer to be compatible with current web standards. This browser requires Vista or Windows 7 to operate.
If you are using Windows XP, the most recent browser is Explorer 8.
FireFox
This is a free down load.
It is faster than Explorer and more secure. Being open source, it is updated regularly to meet current threats and standards, unlike the long development cycle for Explorer.
Chrome
also is available as a free download. Developed by Google, it is fast and easy to use.
Opera
Available free from www.opera.com, this browser, developed in Norway is the preferred browser in many countries.
Safari
, developed first for the Macintosh, it is now also available for Windows
machines.
No longer supported
Internet Explorer on the Macintosh - outdated and very buggy
Netscape 9.0 - Earlier versions are still available but Netscape recommends all Netscape users switch to FireFox or Flock.
Bookmarks
If you have a large file of bookmarks for your browser, you can transfer these to a new browser. or keep the synchronized across multiple browsers, with Xmarks, another free application available at www.xmarks.com.
Emailing
Use Bcc: rather than Cc: for sending multiple copies of your email. See Wikipedia for details on why and how.