As mentioned above a trojan horse virus disguises itself as an innocent looking program in order not to alert the user, when it is downloaded. This makes it difficult to figure out how to remove a trojan horse virus, because it can be hard to identify. One kind of trojan disguise is the filename. It could be something that looks like it is part of the operating system like the Trojan.Win32.Delf.aam, which saves itself as "services.exe". Another more sneaky example is a trojan that installs itself as an Internet Explorer object. It is almost impossible for the average user to spot a trojan horse virus that exhibits this kind of behavior, let alone remove it. To make it even worse there are trojans such as the Win32/FakeAV.ACP, that actually looks and behaves exactly like a security program generating popups with warnings about various threats on the PC. These warnings are of cause fake and how to remove a trojan horse virus like this one is difficult to see.

So what does a trojan horse virus do? Well, if you don’t remove trojans, they can perform a number of malicious actions just like any other piece of malware. This includes generating popup ads, resetting your browser start page, recording your search habits, stealing passwords, etc. In fact, the only thing that sets trojans apart from mother viruses is their ability to disguise themselves, so naturally it is critical to find out how to remove a trojan horse virus as soon as it is discovered.

As with any other kind of malware the course of action when you have to remove a trojan is to run a full system scan with your security program and let it handle the threat. However, the infectious piece of code can have disabled your security program making this impossible, so you can no longer automatically remove the trojan horse virus. In this case you have to identify the particular trojan and search the web for how to remove a trojan like the one you have manually. Some examples below:

- To remove the trojan horse virus Trojan.Win32.Delf.aam you may need to manually stop the windows logon process and reset the Winlogon registry setting to HKLM\SOFTWARE\Microsoft\Windows.
- Others can be much more complicated. If you need to remove the Trojan.Waledac virus manually you will have to identify and kill several processes, delete several windows registry keys, unregister dll's and finally find and delete a number of particular files.
- To manually remove a trojan horse virus in general you can try identifying the process within the windows task manager and then end it. After that you need to do a file search for the trojan file and delete it.

Remember never to remove trojans by just deleting various infected files without having read up on the details of the trojan first. This is not how to remove a trojan because you risk deleting critical files needed by the operating system to function properly. Always try to remove a trojan horse virus with a professional removal program before attempting anything else.

As the above clearly indicates it is not worthwhile to put yourself in a position, where you have to remove a trojan horse virus manually. Always stay safe with a professional security program that can identify, block and remove trojans and other malware.