A PC virus is able to make duplicate copies of itself rapidly once it infects a system. From there, it attempts to spread itself to other computers by sending itself to the contacts of the user's friends and family through email and MSN Messenger.

1. How is a Virus Different from other Types of Malicious Files?

Many people tend to think of any malicious software as a virus when in actual fact, there are many forms of malware that do different things when they infect a system. The other common forms of malware include spyware, adware, worms and keyloggers. A Trojan horse virus will only be activated when the user takes action to run it, and it will attempt to do this by tricking the user to click on links that take them to malicious sites. Only a virus is able to replicate itself and spread to other PCs.

2. Removing a Trojan Horse Virus Quickly

The fastest way that I have used is to download antivirus protection and removal software. This type of PC program contains a database of signature definitions belonging to viruses and other malware. By running a scan and fix on my computer, it was able to detect all the viruses in my system and subsequently delete all of them in less than 30 minutes.

3. How Does a Trojan Horse Removal Software Work?

It is able to find malicious files when it compares all the file signatures in your PC against those in the software's database. Once it has found matches, it will then quarantine the suspicious files for you to confirm if they are indeed malware.