The term 'virus' is frequently used to describe multiple different types of malicious software, collectively known as malware.
Malicious software is a description of computer programs that install themselves on a PC without the user’s knowledge. They can damage computer data, reduce a computer’s performance and allow hackers unauthorised access to both computer and the user’s personal information. If a computer becomes infected with malware it is essential it is removed for both security and performance reasons.
How to Remove a Virus or Malware
Viruses and other types of malware are designed to be difficult to remove and some are specifically programmed to replicate themselves when a user attempts to remove them.
As most modern viruses will spread through computer networks, to entirely eradicate a virus it is essential all infected computers are removed from the network. On a wired network this can be achieved by simply removing the network cable. On a wireless network this will involve either disabling the wireless card or disconnecting/switching off the wireless router.
Virus Removal Tools
Most large antivirus firms will offer removal tools for well known viruses. These can normally be downloaded from their websites by searching for the name of the virus. When installing removal tools it is essential a user follows the instructions provided for effective removal.
On a Windows computer, removing a virus will often require disabling Windows System Restore as modern viruses will keep reverting to an infected restore point if removed.
Removing a virus may also require editing the registry. This should be done with extreme caution and only by following the specific instructions provided.
Antivirus Software and Anti-Spyware
All computers should have up to date antivirus software installed. This should prevent infection by well-known viruses and can also be used to remove existing malware. It is always advisable to purchase antivirus software including anti-spyware to effectively prevent infections.
It is essential the virus definitions database is kept up to date as this is the only way to prevent against newer strains of viruses. Antivirus software is normally purchased with a licence for a certain number of years. Once the licence expires the software will often continue to run. However, it usually won’t download updates meaning the PC is exposed to newer viruses.
If a computer is already infected, some malware will prevent the subsequent installation of antivirus software.
Formatting a Hard Drive
Depending on the severity of the malware, removal tools and antivirus software are sometimes incapable of removing a virus successfully. Whilst it may appear the virus has been eradicated, it will often reappear when a computer is restarted or at a specific time interval.
When all other forms of removal have failed, a last resort is to format the hard drive. This involves deleting everything from the hard disk and starting again. All programs and data will be lost so it is essential data is backed up beforehand.
A hard disk can be formatted by booting the PC from a CD containing the Operating System, a wizard will guide the user through formatting the disk and reinstalling the Operating System. Once installed all other software will need reinstalling.
How to Prevent Viruses and Malware
Prevention of malware is the key to keeping a computer secure. There are a number of factors in helping to prevent a computer becoming infected.
Antivirus software is the most efficient way of preventing viruses and will also assist in removing malware as soon as it infects a system, before it has chance to spread.
Virus Scanning Removable Devices
Many viruses spread through removable media. Therefore it is essential any USB memory sticks, CDs, DVDs, floppy disks etc. are virus scanned before being used in different computers. Most modern antivirus software have built in features for automatically scanning removal devices upon insertion.
Microsoft Antivirus Tools
Microsoft have launched various free tools in an attempt to combat malicious software infecting their Operating Systems.
- Windows Defender- an anti-spyware program designed to prevent and remove any spyware found on a Windows PC
- Microsoft Windows Malicious Software Removal Tool - a tool designed to specifically remove well known viruses such as Blaster, Sasser and Mydoom
- Windows Firewall- a basic firewall included with Operating Systems from Windows XP onwards
Microsoft Updates / Windows Updates
Microsoft frequently release security updates to their software. There is a standard release on the second Tuesday of every month. However, when major software vulnerabilities are discovered there is usually an unscheduled release of a critical update. To keep a computer secure it is essential updates are installed frequently.
Updates can be installed manually through the Microsoft Update website or automatically by switching on Automatic Updates on a Windows PC.
How Computer Users can Prevent Viruses
Even with security updates and antivirus software, users should be aware of the threat of malicious software and the damage it can do.
Files should only be downloaded from trusted websites and email attachments from unknown sources should be opened with extreme caution. Antivirus software should always be up to date and active, removal devices should be scanned and, if a computer exhibits any strange behaviour, a full virus scan should be run.
Katie Giles - Katie lives and works in the United Kingdom. She graduated from university with a BSc in Computer Science and has since worked in both ...
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