The Microsoft Windows Malicious Software Removal Tool helps remove malicious software from your computers that are running Windows 10, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista, Windows Server 2008.. Microsoft releases a new version of the Microsoft Malicious Software Removal Tool every month. After you download the tool, the tool runs one time to check your computer for infection by specific prevalent malicious software (including Blaster, Sasser, and Mydoom) and helps remove any infection it finds.

This article contains information about how the tool differs from an antivirus product, how you can download and run the tool, and what happens when the tool finds malicious software on your computer. The advanced user section includes information for the IT administrator and additional information about how to manage and run the Malicious Software Removal Tool.
Note In compliance with the Microsoft Support Lifecycle policy, the Windows Malicious Software Removal Tool (MSRT) will no longer be offered to or supported on Windows 2000-based systems after July 13, 2010. This date coincides with the end of the Extended Support phase for Windows 2000. For more information about the Support Lifecycle policy, go to the Microsoft Support Lifecycle website.

How the Microsoft Malicious Software Removal Tool differs from an antivirus product

The Microsoft Malicious Software Removal Tool does not replace an antivirus product. It is strictly a post-infection removal tool. Therefore, we strongly recommend that you install and use an up-to-date antivirus product.

The Microsoft Malicious Software Removal Tool differs from an antivirus product in three key ways:
The tool removes malicious software from an already-infected computer. Antivirus products block malicious software from running on a computer. It is significantly more desirable to block malicious software from running on a computer than to remove it after infection.
The tool removes only specific prevalent malicious software. Specific prevalent malicious software is a small subset of all the malicious software that exists today.
The tool focuses on the detection and removal of active malicious software. Active malicious software is malicious software that is currently running on the computer. The tool cannot remove malicious software that is not running. However, an antivirus product can perform this task.
For more information about how to protect your computer, go to the Microsoft Safety & Security Center website.

Note The Microsoft Malicious Software Removal Tool focuses on the detection and removal of malicious software such as viruses, worms, and Trojan horses only. It does not remove spyware. However, you can use Microsoft Security Essentials to detect and remove spyware.
Click here to download Microsoft Security Essentials
You do not have to disable or remove your antivirus program when you install the Microsoft Malicious Software Removal Tool. However, if prevalent, malicious software has infected your computer, the antivirus program may detect this malicious software and may prevent the removal tool from removing it when the removal tool runs. In this case, you can use your antivirus program to remove the malicious software.

Because the Microsoft Malicious Software Removal Tool does not contain a virus or a worm, the removal tool alone should not trigger your antivirus program. However, if malicious software infected the computer before you installed an up-to-date antivirus program, your antivirus program may not detect this malicious software until the tool tries to remove it.