Microsoft Windows Malicious Software Removal Tool is a free tool distributed by Microsoft which checks computers running Windows Vista, Windows XP, Windows 2000, and Windows Server 2003, for malicious software infections and it can also help you to remove any such infections found. An updated version of this Malicious Software Removal Tool is released by Microsoft on the second Tuesday of each month or as needed to respond to security incidents.
Malicious software (also called malware) means a software program that poses a security or privacy risk due to its illegal, viral, fraudulent, or malicious behavior. Viruses, worms, and Trojan horses are all malicious software. The aforesaid Microsoft tool detects and removes only these types of malicious software (including Blaster, Sasser, and Mydoom). It does not remove spyware.
Microsoft itself clarifies that its Malicious Software Removal Tool is not a replacement for an anti-virus product. It is only a post-infection removal tool. Therefore, Microsoft recommends that you should install and use an up-to-date antivirus product for a better safety. Though it has limited utility vis-à-vis a full-fledged anti-virus software, it is still useful in certain situations; and, moreover, it is absolutely free and is made available by Microsoft itself.
It should be noted that the Microsoft Malicious Software Removal Tool removes malicious software from an already-infected computer. On the other hand, an antivirus product would block or prevent a malicious software from running on a computer. Obviously, blocking a malicious software from running on a computer is definitely more desirable than to remove it after infection.
Moreover the said Microsoft tool removes only certain specific prevalent malicious software, which is only a small number of all the malicious software that exists today. However, the major malicious software are covered by this tool.
It is also pertinent to point out that the Microsoft Malicious Software Removal Tool detects and removes only the active malicious software, which means a malicious software that is currently running on the computer (and is thus active) can only be detected and removed by this tool. This tool cannot thus remove a malicious software which is not running on your computer and is in an inactive state. On the other hand, an antivirus product can detect and remove even such inactive malicious software.
In view of these reasons, Microsoft fairly clarifies that the said tool should not be used as a replacement for the regular anti-virus software. A good anti-virus software is a must for protecting your computer from various types of attacks.
At the same time, the Malicious Software Removal Tool is useful if you suspect that your computer is already infected by a malicious software and you do not have a regular anti-virus software installed on your computer. It is thus useful for such a situation as a free utility.
This tool can be downloaded easily by turning on the Automatic Updates in your Windows operating system (only Windows Vista, Windows Server 2003, Windows XP, and Windows 2000, are supported). This will ensure that you receive the tool automatically every month. You can also download it manually from this Microsoft site.
Normally this tool runs silently in the background (i.e., in the quite mode) to check for infections on your computer. It runs a quick-scan for the worst infections. However, if you want to use this tool to run a more thorough scan of your computer, you can run it manually. But, please be aware that the full scan can take a lot of time to complete because it will scan all fixed and removable drives.
To run the tool manually, click on the Start button and then click on the Run option. Then type “mrt” and click OK button to start the tool. If your tool is already up-to-date, it will show the following screen:
You can select one of the three modes in which to conduct the malicious software check:
- Quick scan: Only those areas of the system will be scanned which are most likely to contain malicious software. However, full scan may be prompted if some such malicious software is found during the quick scan.
- Full scan: Scans the full system, but it could be time-consuming.
- Customized scan: In addition to the quick scan, it will offer scan of a user-defined folder.
The Malicious Software Removal Tool will now scan your computer for the infections and the following screen will be presented to you:
After, the scan is completed, you can view the results by viewing the report in the following form:
If any malicious software has modified (i.e., infected) any files on your computer, this tool will prompt you to remove the malicious software from those files. Similarly, if any malicious software has modified your browser settings, your homepage may be changed automatically by the tool to a page which gives you directions on how to restore those settings. You have the option to clean specific files or all the infected files that this tool finds for you.