In some respects computer viruses are like biological viruses, such that they can range from the mildly annoying to the downright harmful.
Annoying viruses can cause random reboots and crashes whilst the more harmful ones can damage and delete critical files, or open up gateways for other forms of attack.
Preventing viruses is a reasonably simple affair most of the time – installing a quality anti-virus program and keeping it updated and running is usually sufficient.
Additionally, always remember to never open email attachments unless you are absolutely certain that the content is trustworthy.
Even so, it is still likely that your computer will become infected with a virus one day.
The likely symptoms of such an infection include weird behaviour from your operating system and the loss of important data or programs.
If, or when, that happens what do you do?
Firstly, don’t panic, as any problems that you have noticed with your PC may not be caused by a virus at all.
Secondly, if you do have a virus then you will need to identify it before looking for a cure.
If your computer is functioning to a degree then you may be able to run your anti-virus program or install one from a disk if you have lost your internet access (you could ask a friend to download a free anti-virus program or check out the PC magazines in your local store who often place such programs on their ‘free’ DVDs that come attached).
Some viruses will prevent your anti-virus program from updating in order to prevent you from acquiring the tools to remove them.
If that is the case, and you still have internet access, then you may be able to find a website that will run an online scan on your system.
Be very careful which service you choose, however, as there are a lot of anti-virus scams out there that utilise online scans as a means of compromising your system.
If you are using the Windows operating system then there are another couple of options open to you that may work.
When Windows starts up choose the option called ‘Last Known Good Configuration’ which may just allow you to boot up without the virus running and then remove it before rebooting your machine.
Such an option doesn’t work often but you may get lucky.
Likewise, you may also be able to boot your system in ‘safe mode’ which may just leave you enough functionality to remove the virus.
Additionally, Windows users may need to repair damaged entries in the Registry.
Again, I won’t recommend a specific repair tool as there are some dodgy ones out there so you will need to do your homework before downloading or using one.
The final, and most drastic, option is to delete your operating system and start again with a fresh install which is achieved by reformatting your hard drive and then installing your OS from the disk that you either purchased or that came with your computer.
This is guaranteed to get rid of any and all infections but at the cost of all your data and programs which is why it is wise to always keep backups of everything of importance.
Of course after initiating a fresh install of your operating system it would be wise to get your anti-virus program installed and running immediately as well as other security measures, such as a firewall, anti-spyware, etc.