Worms, trojans, polymorphic viruses, logic bombs, boot sector viruses...... It doesn't end!
These are all terms we may or may not have heard of, in reality every one has faced one of these somewhere down the line!
So what are they and what do they do?
Computer viruses are a small piece of software that are designed to spread from one computer to another and create havoc in your computer system.
Computer viruses are often spread through email attachments, instant messaging, downloading music/photos from unknown sources or not having an updated anti virus program installed.
What can we do to prevent a virus?
The first thing is to make sure your running an up to date anti-virus/internet security program. Chances are if you've just purchased a new PC you've probably been gifted with a 30 or 60 day trial, this can be an easy trap to step into as once your trial ends you're generally not notified and this is were the problem begins! Your system is now unprotected!
This doesn't mean you have to rush out and spend $99.00 on a program - for a free alternative try AVG Free : www.avg.com.au/free
All anti-virus programs will run a scheduled scan every couple of days and even when your PC is turned on making it easier for the user to keep tabs of their computer.
The second thing we need to do is run an Anti-spyware program.
Anti-spyware software helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software. Its not unusual for some anti-virus programs to miss these types of files and thus the need for anti-spyware software.
Last but not least we recommend being mindful of what websites you visit, opening emails from people you don't know and obtaining files from other computers.  
With these simple steps in place you'll be on the right track to having a healthy and reliable computer system.
Here's our top 6 picks for anti-virus/spyware removal software.
Internet Security

• Kaspersky internet security - http://www.kasperskyanz.com.au
• McAfee internet security - http://www.mcafee.com.au
• Trend Micro internet security - http://www.trendmicro.com.au

Spyware removal

• CCleaner spyware removal - http://www.piriform.com/ccleaner
• Malwarebytes spyware removal- http://www.malwarebytes.org/
• Spybot search and destroy spyware removal - http://www.safer-networking.org