For those unfamiliar with the term, computer viruses are malicious items of software, usually transmitted by email, which can harm your computer in various ways including the corruption of essential files.
Why anybody would want to do this to complete strangers is a mystery though it has become an increasing problem with the growth of the internet.
Adware, usually downloaded involuntarily from web sites, tends to clog-up your PC with unwanted pop-up advertisements.
Malware is really a generic term for a whole range of malicious software whose intent is to cause damage—with computers, new jargon words for the same concept spread even quicker than viruses.
Spyware, another variation on the theme, attempts to extract confidential information such as usernames and passwords whose disclosure could seriously damage your wealth.
Illegal music download sites seem to be the main source of these infestations with 'porn' and 'get-rich-quick' sites coming a close second.
It is also possible for hackers to access your PC directly via the internet, making those with ‘always-on’ broadband connections particularly vulnerable.
The bottom line is that up-to-date protection against these ever-expanding threats is essential.
For the personal and small-business user, the biggest names in the market are Norton and McAfee whose ‘internet security’ products incorporate antivirus and anti spyware/adware functionality together with a ’personal firewall’ to prevent unauthorised access to your PC.
Both products include the ability to automatically check for software updates and ‘virus definitions’ to protect against new threats.
I have included Norton and McAfee web site links for reference and technical support resources though you can generally buy both companies’ products cheaper elsewhere (on Amazon and eBay, for example).
Many Internet Service Providers will also scan email for viruses before they send it on—ISPs tend to use the more-expensive ’corporate’ internet security services where the protection against new threats is updated on a continuous basis rather than once every few weeks.
However, that doesn’t remove the need for comprehensive protection on your own PC as threats come from a variety of sources.