A computer virus is much more than just an inconvenience.

Beware of Trojans, viruses and spyware

Your computer may be infected by a 'Trojan', a virus or spyware if it starts to behave in an unpredictable manner. Consider the following warning signs:

• Your system may take longer than normal to start, or have a slower response time when opening files
• Files may become corrupted, might not load or you might experience a system crash
• Your anti-virus software may generate a warning message, or other unusual messages may appear on screen

Bear in mind that your computer could still be infected even if nothing appears to be different.

Install and maintain anti-virus software

Good anti-virus software protects your computer. It's designed to detect and remove any computer viruses, Trojans and spyware that may have been installed on your computer without your knowledge or permission. These invaders can infect your computer and affect your online security.

Your anti-virus software should be regularly updated to keep the latest known threats at bay.