updated: January 28, 2010
Trojan horses are malicious programs that may appear to be legitimate but actually harm your computer. Trojans place unusual and unremovable icons on your desktop and some take control of your computer. Many disable functions and programs like the Windows Task Manager. It is often necessary to use multiple techniques to remove a Trojan virus permanently.
Difficulty: Moderately Easy
Instructions
- Download and install an anti-malware or antivirus program that handles Trojan viruses. Malwarebytes' anti-malware is one such program and was recommended by CNET editors in April 2009; this program removes stubborn viruses and Trojans that other typical antivirus programs cannot remove.
- Run the anti-malware program on your computer. Choose the full scan option so that the program scans all your hard drives as well as hidden files and folders. Close all other programs while the anti-malware program is running so that it operates quickly and efficiently.
- Review the results that the anti-malware program displays. Choose the option to "delete" or "remove" infected files that contain Trojan viruses. Take note of any files that the program was not able to eradicate as these should be listed; the program may list DLL files or similar directories where the Troan resides.
- Open the command prompt box to remove any DLL files of the Trojan. Click on "Start," then "Run," type in "cmd," and hit "Enter" to open the command prompt box. Type "cd" followed by the directory in which the Trojan is located. To unregister the DLL file, type the command "regsvr32 /u <filename>.dll" where <filename" is the name of Trojan DLL file. Close the command prompt box.
- Open the Windows Registry to remove Trojan-infected registry files. Click on "Start," then "Run," type in "regedit" in the command prompt box to open it. Look for and delete the registry files infected by the Trojan virus. Go to McAfee's free virus information at "home.mcafee.com/virusInfo/" to find the latest, updated information on Trojan viruses and which registry entries could possibly be infected.
- Confirm that the Trojan virus has been deleted. Perform a full scan using an anti-malware or antivirus software program. Check the results of the scan. Make sure that there are no Trojans or viruses listed as files unable to be removed by the program.
