The fact of the matter is that security companies such as McAfee and Symantec depend on the existence of viruses. It wouldn't surprise me if these companies themselves were writing viruses, so they can claim their software detects more viruses than their competitors, or that they have the only antidote to a particular virus.
These companies spend millions of dollars on scaremongering -- trying to convince you that using antivirus is the only solution. In reality, antivirus software is about as effective as installing airbags on a plane. They'll make you feel safer, but they're totally pointless.
So, let's take a step back and consider why antivirus doesn't work. When you browse in the Internet or open a email attachment, you are essentially letting someone -- potentially a malicious attacker -- have complete access to your computer. By visiting a website or opening that attachment, you are saying "I trust the person who wrote this".
Antivirus software works by trying to detect a small subset of behaviour that can be classified as "malicious". But it can't possibly stop all malicious behaviour, just like the Police can't stop everyone from speeding. When AV software stops one method, new methods are found. It's an endless cycle.
But your operating system already has a built in mechanism to thwart 99% of this malicious behaviour -- right out of the box. It's called a "Limited User Account".
For almost a decade, operating systems have supported tight controls over the privileges individual users have. Everything from being able to access particular folders on your hard disk through to whether you're allowed to install software.
If you're running Windows 2000, Windows XP Pro, or Windows Vista, your computer already has this functionality. Here's how to use it.
As a limited-user, you can have the confidence to say "goodbye" to your antivirus software. Your computer runs faster, and you have no nagging screens screaming to update the virus definitions. Because you yourself aren't permitted to install software and modify system files, neither are viruses or spyware.