If you ask a computer security consultant whether you should worry about computer viruses, chances are that you will get a non committal answer like "well, that all depends"… and rightly so. There are, after all, many parameters that must be analyzed before assessing a person’s virus vulnerability. In fact, it is like asking whether one should walk around being worried about germs!
Here are a few things to consider. Computer viruses can be transmitted through emails, programs, websites, pen drives, CDs, floppies (if anyone still uses them!) USB devices, across networks... the list goes on. They can infect your PC with or without your knowledge. Some of them are capable of paralyzing your PC or even completely destroying your data. Unchecked, they are can exist indefinitely as long as they have a host. And if that doesn't make you flinch, consider the fact that over a million viruses are said to have been created! http://news.bbc.co.uk/2/hi/technology/7340315.stm
However, that's only one side of the coin. It is worth noting that many viruses are relatively innocuous and have a limited impact on the PCs they affect. Most viruses are designed to attack specific file types and they rarely infect all the files on your PC. Furthermore, for every virus that is created, the anti-virus software antidote is created within days, if not hours. Most anti-virus companies provide regularly updated virus definitions for bonafide users of their software thereby giving them protection from known viruses.
Toss into the equation the fact that only a small fraction of emails actually carry viruses. Falling storage costs permit more frequent data back-ups which, in turn, mean that recovery from virus attacks can be quick and complete, as long as one is diligent in taking those back ups. Looking at the flip side, again, one must note that we live in a world where being ‘connected’ is the norm and interoperability across gadgets is the way forward. The ever-growing number of devices that viruses can potentially affect means that the risk of encountering one will increase with time.
In my view, here's the bottom line. Viruses can, indeed, pose significant threats to your PC and data. If you are unlucky and are struck by a truly malicious virus then all the statistics in the world supporting the notion that most viruses are more irritating than devastating will be meaningless. However, that need not be the case. If you are cognizant of the risks and are careful… then you can look forward to stress free computing experience. The idea should be to take proactive steps to protect your PC against viruses, to have solid recovery plans in place and to exert uncompromising caution at all times. If you do that, the threat of a virus infecting your PC will not keep you up at night.