Urdu Poetry Forum

Manual steps to download and run the Windows Malicious Software Removal Tool

If you are an IT administrator who wants more information about how to deploy the tool in an enterprise environment, click the following article number to view the article in the Microsoft Knowledge Base:891716 (Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment) Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment
This article includes information about Microsoft Systems Management Server (SMS), Microsoft Software Update Services (SUS), and Microsoft Baseline Security Analyzer (MBSA) support. Microsoft Update Web site, Windows Update Web site, and Automatic Updates

Windows Vista, Windows XP, Windows Server 2003, or Windows 2000 users

( You can use the Microsoft Update Automatic Update functionality to download and run the tool, or you can visit the Microsoft Update Web site: Microsoft UpdateMicrosoft Update)
Windows Vista, Microsoft Windows XP, or Microsoft Windows Server 2003 SP1 users who are not yet using Microsoft Update

You can use the Windows Update Automatic Updates functionality to download and to run the tool, or you can visit the Windows Update Web site: Microsoft Windows Update (Microsoft Windows Update)
Notes

•	The tool is offered as a critical update through the Microsoft Update, Windows Update, and Auto Update mechanisms.
•	The first time that you download and run the tool by using Microsoft Update, Windows Update, or Automatic Updates, you must accept a specific end user license agreement (EULA). The EULA is displayed when you log on as a member of the Administrators group and then access Automatic Updates, the Windows Update Web site, or the Microsoft Update Web site.
•	A new version of the tool will be released each month and will be made available from Automatic Updates, from the Windows Update Web site, and from the Microsoft Update Web site.

For more information about Automatic Updates, click the following article number to view the article in the Microsoft Knowledge Base: 294871 (Description of the Automatic Updates feature in Windows) Description of the Automatic Updates feature in Windows
Microsoft Download Center

You can download the Malicious Software Removal Tool manually from the Microsoft Download Center. The following file is available for download from the Microsoft Download Center:

Download the 890830 package now. (Download details: Windows Malicious Software Removal Tool)


Release Date: November 13, 2007

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base: 119591 (How to obtain Microsoft support files from online services) How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file. Malicious Software Removal Tool Web site on Microsoft.com

To download and run an online version of the Malicious Software Removal Tool, visit the following Malicious Software Removal Tool Web site: Malicious Software Removal Tool (Malicious Software Removal Tool)
Known issues

•

Typically, when you run the Windows Malicious Software Removal Tool, the tool creates a randomly named temporary directory in the root drive of your computer. This directory will contain several files and includes the Mrtstub.exe file. Most of the time, this folder will be automatically deleted after the tool has finished running or after the next restart. Sometimes, this folder may not be deleted automatically. In these cases, this folder can be deleted manually and has no adverse effect on the computer.

•

A user may log on to a computer at the same time that the Windows Malicious Software Removal Tool is running in the background. (The tool may be running as part of a deployment that uses Windows Server Update Services.) In this case, Windows may inform the user that the current user profile is corrupted and that a new profile is being created. To resolve this issue, the new profile can be removed. The user can logon to the system again at a time when the tool is not running. This issue is most likely to occur on a Windows 2000-based computer.

Known issues in the November 8, 2005 release

When you run the November 8, 2005 release of the Windows Malicious Software Removal Tool from Windows Update, from Automatic Update, or from the Download Center, the tool may appear to stop responding. Additionally, you may experience one of the following symptoms:

•	When you run the tool from Windows Update or from Automatic Update, Windows Task Manager shows that the Iexplore.exe process has high CPU usage.
•	When you run the tool from the Download Center, Windows Task Manager shows that the Mrt.exe process has high CPU usage.

To resolve this issue, install the updated version of the Windows Malicious Software Removal Tool that is now available from Windows Update, from Microsoft Update, from Automatic Updates, or from the Download Center.

Note To stop the Mrt.exe process or the Iexplorer.exe process when the process has high CPU usage, follow these steps:

1.	Press CTRL+ALT+DELETE.
2.	Click Task Manager, and then click the Processes tab.
3.	Stop the process for the task that has high CPU usage. To do this, right-click the task, and then click End Process.
4.	Click Close.

Release information

The Malicious Software Removal Tool is released on the second Tuesday of every month. Each release of the tool helps detect and remove current, prevalent malicious software. This malicious software includes viruses, worms, and Trojan horses. Microsoft uses several metrics to determine the prevalence of a malicious software family and the damage that can be associated with it.

The following table lists the malicious software that the tool can remove. The tool can also remove any known variants at the time of release. The table also lists the version of the tool that first included detection and removal for the malicious software family.

Each release of the tool is cumulative. That is, each release not only helps detect and remove new malicious software families, it also helps detect and remove all the malicious software covered in earlier versions. New variants of malicious software that is detected and removed in previous releases are also covered in each monthly release.

This Microsoft Knowledge Base article will be updated with information for each monthly release so that the number of the relevant article remains the same. The name of the file will be changed to reflect the tool version. For example, the file name of the January 2005 version is Windows-KB890830-ENU.exe, and the file name of the February 2005 version is Windows-KB890830-V1.1-ENU.exe.

Prerequisites

Except where noted, the information in this section applies to all the ways that you can download and run the Malicious Software Removal Tool:

•	Microsoft Update
•	Windows Update
•	Automatic Updates
•	The Microsoft Download Center
•	The Malicious Software Removal Tool Web site on Microsoft.com

For you to run the Malicious Software Removal Tool, the following conditions are required:

•

The computer must be running Windows Vista, Windows Server 2003, Windows XP, or Windows 2000.

•

You must log on to the computer by using an account that is a member of the Administrators group. Note The first time that you download and run the tool by using Automatic Updates, Microsoft Update, or Windows Update, you must be logged on to the computer by using an account that is a member of the Administrators group. After you accept the one-time EULA, you can receive future versions of the tool without being logged on to the computer as an administrator.

If the computer and logon account do not meet these conditions, the tool will not run on the computer.Command-line switches

The Malicious Software Removal Tool supports four command-line switches:

•	/Q or /quiet - Use quiet mode. This option suppresses the user interface of the tool.
•	/? - Display a dialog box that lists the command-line switches.
•	/N - Run in detect-only mode. In this mode, malicious software will be reported to the user but will not be removed.
•	/F - Force an extended scan of the computer.
•	/F:Y - Force an extended scan of the computer and automatically clean any infections found.

Usage information

Important Before you follow these steps, make sure that you have backed up all important data.

When the Malicious Software Removal Tool runs, the tool performs the following functions. Except where noted, the tool has the same behavior independent of what command-line switches you use or how you download and run the tool. Note that the tool is not actually installed on a computer. Therefore, no entry is created for it in the Programs folder or in Add or Remove Programs.

Notes

•	When you download the tool from Microsoft Update, Windows Update, or from Automatic Updates, and no malicious software is detected on the computer, the tool will run in quiet mode. If malicious software is detected on the computer, the next time that an administrator logs on to the computer, a balloon will appear in the notification area to notify you of the detection. To find more details about the detection, click the balloon.
•	When you run the tool from the Web site Microsoft Corporation (Microsoft Corporation), the tool always displays a user interface (UI).
•	When you download the tool from the Microsoft Download Center, the tool ordinarily displays a UI when it runs. However, if you supply the /Q command-line switch, it runs in quiet mode.
•	Extended scan and file disinfection functionality currently are not supported when you run the tool from the Malicious Software Removal Tool Web site. Run the tool from the Download Center, from Microsoft Update, from Windows Update, or from Automatic Updates to enable this functionality.

Prerequisite check

•	If your logon account does not have the required permissions, the tool exits. If the tool is not being run in quiet mode, it displays a dialog box that describes the failure.
•	If the computer is not running a required operating system, the tool exits.
•	If the tool is more than 60 days out-of-date, the tool displays a dialog box that recommends that you download the latest version of the tool.

EULA display

If the prerequisites are met, the tool displays the EULA. For the tool to continue to run, you must accept the EULA.

•	If you receive the tool from Microsoft Update, from Windows Update, or from Automatic Updates, the EULA is displayed only the first time that you run the tool.
•	If you download the tool from the Download Center, you only have to accept the EULA once. After the EULA is accepted once, it will not be displayed again. The EULA is not displayed if you run the tool in quiet mode.
•	If you download the tool from the Microsoft.com Web site, the EULA is displayed every time that you run the tool.

Select a type of scan

•	After the EULA has been accepted, the user can select a type of scan to perform. Only users of the Download Center version of the tool will see this screen.
•	A quick scan is the default scan type. Sometimes, if malicious software is found, the user may be prompted to perform a full scan also.
•	A full scan performs a quick scan and then a full scan of the computer, regardless of whether malicious software is found during the quick scan.
•	A customized scan performs a quick scan and then a scan of a specific folder and its subfolders on the computer.

Quick scan for malicious software

•	After the EULA has been accepted, the tool scans computer memory for known malicious software and stops any malicious processes that are found. It also deletes files and registry keys that are associated with processes that are identified as malicious.
•	The scan searches only for malicious software that is active on a system. The tool does not perform an extended scan at this point.
•	If you download the tool from the Download Center, you will see a status bar that indicates the scan is progressing.
•	If the malicious software modified your browser settings, your homepage may be changed automatically to a page that gives you directions on how to restore these settings.

Extended scan for malicious software

•	If certain malicious software is detected on the computer, the tool will prompt you to perform an extended scan of the computer. We recommend that you perform this scan.
•	This scan can take several hours to complete because it will scan all fixed and removable drives for malicious software.
•	Mapped network drives will not be scanned.

To clean infected files

•	If malicious software has modified (or infected) user files on the computer, the tool will prompt you to remove the malicious software from those files. You can choose to clean specific files or all infected files found.
•	Note that some data loss is possible during this process and that the tool may not be able to restore some files to the original, pre-infection state.

Recording scan data

•	After the scan is complete, the tool creates a log file that contains the results of the scan. The name of the file is Mrt.log. The file is in the %windir%\Debug folder.
•	This log file is available in English only.

Displaying results

•	After the tool has run and if quiet mode is not active, the tool displays the results of the scan.
•	See the “Possible results” section for a description of the information that the removal tool can return.

Reporting infection information

•	If the tool detects malicious software or if an error occurs when the tool is running, the tool sends a report to Microsoft that contains basic information about the malicious software or about the error. No identifiable personal information that is related to you or to the computer is sent together with this report.
•	For details about the information that is sent to Microsoft, see the "Reporting component" section.
•	If you do not want to send this information to Microsoft, you can disable the reporting component. For more information about disabling the reporting component, click the following article number to view the article in the Microsoft Knowledge Base: 891716 (Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment) Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment
•	If suspicious files are found on the computer, you will be prompted to submit additional information about these files.

Possible results

After the tool runs, there are four main results that the removal tool can report to the user:

•	No infection was found.
•	At least one infection was found and was removed.
•	An infection was found but was not removed. This result will be displayed if suspicious files were found on the computer. To help remove these files, you should use an up-to-date antivirus product.
•	An infection was found and was partially removed. To complete this removal, you should use an up-to-date antivirus product.

The removal tool may also suggest the following additional actions to the user:

•	Computer restart The removal tool may request a restart to complete the removal of some malicious software.
•	Manual steps The removal tool may prompt you to perform manual steps to complete the removal of some malicious software

Reporting component

As noted in the "Usage information" section, the Malicious Software Removal Tool will send information back to Microsoft if the tool detects malicious software or finds an error. This information will be used for tracking virus prevalence. For information about how to disable the reporting component and how to prevent this tool from sending information to Microsoft, click the following article number to view the article in the Microsoft Knowledge Base: 891716 (Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment) Deployment of the Microsoft Windows Malicious Software Removal Tool in an enterprise environment
The specific information that is sent to Microsoft consists of the following items:

•	The name of the malicious software that is detected
•	The result of malicious software removal
•	The operating system version
•	The operating system locale
•	The processor architecture
•	The version number of the tool
•	An indicator that notes whether the tool is being run from Microsoft Update, from Windows Update, from Automatic Updates, from the Download Center, or from the Web site.
•	An anonymous GUID
•	A cryptographic one-way hash (MD5) of the path and file name of each malicious software file that is removed from the computer

If apparently malicious software is found on your computer, the tool prompts you to send information to Microsoft beyond what is listed above. You are prompted in each of these instances, and this information is sent only with your consent. The additional information is:

•	The files that are suspected to be malicious software. The tool will identify the files for you.
•	A cryptographic one-way hash (MD5) of any suspicious files that are detected.

No other information is sent to Microsoft.Interaction with antivirus software

You do not have to disable or to remove your antivirus program when you install this tool. However, if your antivirus program is running on a computer that is infected with prevalent malicious software, 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.

The Microsoft Malicious Software Removal tool does not contain a virus or a worm. Therefore, the removal tool alone should not trigger your antivirus program. However, if malicious software infected your computer before an up-to-date antivirus program was installed, and if scheduled virus scanning or background virus scanning is disabled, your antivirus program may not detect this malicious software until the tool tries to remove it.