With any computer connected to the Internet there is always the threat of a virus attack. Most new computers come with a trial edition of an anti-virus program. Sadly, many business individuals insist on gambling with their computers by leaving them vulnerable to attack when anti-virus software is allowed to expire.
In many cases the business will also fail to install Firewall protection and they may not even be aware of the dangers of Spyware.
Not every site you visit will be a safe place. Not every email you receive will contain safe information. Many viruses enter a website when users visit certain websites (predominately pornographic sites). These viruses can also come from certain emails.
I once had a computer that somehow disengaged the anti-virus software due to a virus attack. In a few short weeks the virus devoured over 20,000 files on my computer. This was a hard lesson, especially since I had a fully paid version of anti-virus software on my computer at the time.
I was told that this was a very rare case, but was also advised to ensure that I checked regularly for updates and scanned my computer for viruses everyday, which is something...