In the computer world, the words “Trojan” and “worm” are not exactly the same thing, although many people believe that they are. True, a Trojan and a worm are both malicious programs that can damage your computer. And in some cases, they can damage your computer beyond repair. Another similarity is that Trojans and worms can be removed from your computer. The key to Trojan and worm removal, however, is to understand the differences between the two.

A Trojan or “Trojan Horse” is actually a wolf in sheep’s clothing. It will present itself as helpful program, but once you install it on your computer, it will wreak havoc on your system almost immediately. A Trojan Horse may appear in the form of a file or software program that has been sent from a legitimate source. The Trojan Horse will install and a number of things can happen. Some Trojans will simply rearrange your desktop or add annoying icons to your desktop and others will delete files. Some of the more advanced Trojans can open the door to predators looking to steal your identity. These types of Trojans can give users unlimited access to your system. Trojans do not reproduce or replicate. Worms, on the other hand, can reproduce, self-replicate and infect other files.

Worms are a sub-class of viruses. They can spread from computer to computer, travel across networks, copy your address book and send itself out to everyone in it, and it can freeze or disable entire servers. Some of the most sophisticated worms can actually tunnel into your computer and give users remote access to your computer. One of the most notorious of these is the Blaster Worm. The Blaster Worm, created in part by an 18-year-old kid from Minnesota back in 2003, spread on computers running Windows XP and Windows 2000. The worm was also called “Lovsan” and “Lovesan.”

To get rid of malicious software there are a number of free Trojan and worm removal software downloads available on the web. The problem is that you have to make sure that the download is from a trusted source. If you are running Windows, stick with Microsoft software downloads. Microsoft offers its “Windows Malicious Software Removal Tool” free of charge for its Windows operating system. The great thing about this free Trojan and worm removal tool is that it updates once a month and reports if malicious software is found.

Other malicious software and worm removal tools include: Norton AntiVirus and McAfee Antivirus. These software programs are not free. It is important to note that while the Microsoft Software Removal Tool helps remove infections, it does not prevent them. If you want added security, it’s best to install Norton or McAfee as well.

From Microsoft:

The Microsoft Windows Malicious Software Removal Tool checks Windows XP, Windows 2000, and Windows Server 2003 computers for and helps remove infections by specific, prevalent malicious software including Blaster Worm, Sasser, and Mydoom. When the detection and removal process is complete, the tool displays a report describing the outcome, including which, if any, malicious software was detected and removed. The tool creates a log file named mrt.log in the %WINDIR%\debug folder.

Version 1.30 adds Win32/Allaple to the list of malicious software this tool detects.

You can download directly from the Microsoft website or Cnet.com.