First of all, you have to download and install the software to remove the malicious software. If you have a registered Windows, you can simply download the official antivirus software from Microsoft website.
In contrast, if the version of your Windows is not registered, you will not be able to install the software. Then, you can either register your Windows or you can install any other antivirus software. You must know that there are many types of antivirus software (Norton, Avira, AVG, F-secure, McAfee and Kaspersky etc) which are freely available on the internet.
After installing the virus removal tool, open it by clicking on its icon on the desktop or by going to the start menu.
Now, click on the ‘Full Scan’ option if you want to clean your PC from all the Trojans. It is very important for you to know that full scan will take a lot of time to complete the process. So, if you don’t have much time, you can select the ‘Quick Scan’ option.
Expectantly, the Trojan Agent.Ahrn will be removed by running the quick scan. However, if it is not removed, you will have to select the full scan option.
To take the required actions against all the Trojans detected by the malicious software removal tool, you just have to follow the guidelines on your screen. It is better to remove the files containing virus completely. But, if your files are important, you can put them in quarantine.
You will have to restart your computer so as to complete the Trojan removal process.