Microsoft Security Essentials Free Antivirus

About Microsoft Security Essentials

Use Microsoft Security Essentials to guard against viruses, spyware, and other evil software. It provides real-time protection for your home or small business PCs.

Microsoft Security Essentials is free* and we designed it to be simple to install and easy to use. It runs quietly and efficiently in the background so you don't have to worry about interruptions or making updates. 

Minimum system requirements for running Microsoft Security Essentials

Microsoft Security Essentials is free* and easy to download. Here's what you need to run it:

Operating System: Windows XP Service Pack 3 (SP3)*; Windows Vista (Service Pack 1, or Service Pack 2)*; Windows 7*

• For Windows XP, a PC with a CPU clock speed of 500 MHz or higher, and 256 MB RAM or higher.
• For Windows Vista and Windows 7, a PC with a CPU clock speed of 1.0 GHz or higher, and 1 GB RAM or higher.
• VGA display of 800 × 600 or higher.
• 200 MB of available hard disk space.
• An Internet connection is required for installation and to download the latest virus and spyware definitions for Microsoft Security Essentials.
• Internet Browser:
  • Windows Internet Explorer 6.0 or later.
  • Mozilla Firefox 2.0 or later.
• Microsoft Security Essentials also supports Windows XP Mode in Windows 7. For more information see the system requirements for Windows XP Mode in Windows 7. 

  Specific features

  History

  What this feature does: This feature provides a list of all malware or suspected malware that Microsoft Security Essentials detected on your PC and the actions that were taken when these programs were detected. The information displayed in the History tab is for items detected for all users - not per user.

  Information collected, processed, or transmitted: A list of all malware or suspected malware that Microsoft Security Essentials detected on your computer and the actions taken on these items are stored on your computer. These lists include Microsoft Security Essentials activity for all the local users on the computer. The lists are sent to Microsoft as part of your basic membership in MAPS.

  Choice and control: History lists may be deleted by the local computer administrator. By default, all items are displayed for all users. To allow only the local computer administrator to view all items, in the Settings tab, select the Advanced tab and clear the option "Allow all users to view the full History results."

  Microsoft Update

  What this feature does: Microsoft Security Essentials turns on automatic updating from Windows Update and Microsoft Update to help keep your computer current with updates to Windows and other Microsoft software. This means any software using Windows and Microsoft Update will be impacted by this change. Microsoft Update is essential to providing you with the latest malware threat definition updates for Microsoft Security Essentials.

  Information collected, processed, or transmitted: For more information about Windows Update and Microsoft Update, see the Update Services Privacy Statement at http://go.microsoft.com/fwlink?LinkID=76234.

  Choice and control: Windows Update and Microsoft Update are turned on by default in order to provide you with the current software and virus signature updates. If you would like to later turn updates off, you can do so through Windows settings. To learn how, see the Update Services Privacy Statement at http://go.microsoft.com/fwlink?LinkID=76234.

  Automatic scanning for malware

  What this feature does: Microsoft Security Essentials includes an automatic scanning feature, which scans your computer and alerts you if it detects malware. You can turn automatic scanning on or off and change the frequency and type of scans using the Microsoft Security Essentials Settings tab. You can also choose which actions are automatically applied to software that Microsoft Security Essentials detects during a scheduled scan. For severe/high threats, certain actions will automatically be taken by default to remove the malicious software and protect your computer from potential further infection. Once the malicious software is removed, Microsoft Security Essentials may also reset some Windows settings (such as your home page and search provider). For low/medium threats, we will prompt you to take an action. To modify the actions taken in response to these threats, see the Choice and Control section below.

  Information collected, processed, or transmitted: A list of all malware or suspected malware that Microsoft Security Essentials detected on your computer and the actions taken on these items are stored on your computer. These lists include Microsoft Security Essentials activity for all the local users on the computer. The lists are sent to Microsoft as part of your basic membership in MAPS.

  Choice and control: While not recommended, you can turn off automatic scanning using the Microsoft Security Essentials Settings tab. You can also configure the actions taken for each level of threats in the "Settings" panel of Microsoft Security Essentials.

  Real-time protection

  What this feature does: Microsoft Security Essentials' real-time protection feature alerts you when viruses, spyware and other potentially unwanted software attempts to install itself or run on your PC. For severe/high threats, certain actions will automatically be taken by default to remove the malicious software and protect your computer from potential further infection. Once the malicious software is removed, Microsoft Security Essentials may also reset some Windows settings (such as your home page and search provider). For low/medium threats, we will prompt you to take an action. To modify the actions taken in response to these threats, see the Choice and Control section below.

  Information collected, processed, or transmitted: A list of all malware or suspected malware that Microsoft Security Essentials detected on your computer and the actions taken on these items are stored on your computer. These lists include Microsoft Security Essentials activity for all the local users on the computer. The lists are sent to Microsoft as part of your basic membership in MAPS.

  Choice and control: While not recommended, you can turn off real-time protection using the Microsoft Security Essentials Settings tab. You can also configure the actions taken for each level of threats in the "Settings" panel of Microsoft Security Essentials.

  Shell extension

  What this feature does: Shell extension is a scanning tool, which lets you select specific files and/or folders and scan them using Microsoft Security Essentials.

  Information collected, processed, or transmitted: A list of all malware or suspected malware that Microsoft Security Essentials detected on your computer and the actions taken on these items are stored on your computer. These lists include Microsoft Security Essentials activity for all the local users on the computer. These lists are sent to Microsoft as part of your basic membership in MAPS.

  Choice and control: The shell extension feature is a manual tool that you can choose to use or not.

  Microsoft Active Protection Service (MAPS)

  What this feature does: The Microsoft Active Protection Service (MAPS) antimalware community is a voluntary, worldwide community that includes Microsoft Security Essentials users. If Microsoft Security Essentials is turned on, MAPS can report malware and other forms of potentially unwanted software and errors encountered in Microsoft Security Essentials to Microsoft. If a MAPS report includes details about malware or potentially unwanted software that Microsoft Security Essentials may be able to remove, MAPS will download the latest signature to address it. MAPS can also find "false positives" (where something originally identified as malware turns out not to be) and fix them.

  Information collected, processed, or transmitted: This feature sends reports about errors, malware, and potentially unwanted software to Microsoft. These reports include information about the files or apps in question, such as file names, cryptographic hash, vendor, size, and date stamps. In addition, MAPS might collect full URLs to indicate the origin of the file, which might occasionally contain personal information such as search terms or data entered in forms. Reports might also include the actions that you applied when Microsoft Security Essentials notified you that software was detected. MAPS reports include this information to help Microsoft gauge the effectiveness of Microsoft Security Essentials' ability to detect and remove malware and potentially unwanted software.

  If Microsoft Security Essentials and MAPS are both enabled on your PC, MAPS reports will be automatically sent to Microsoft when Microsoft Security Essentials:

  • detects software or changes to your PC by software that hasn’t been analyzed for risks yet;
  • applies actions to malware (as part of its automatic remediation) upon detection;
  • completes a scheduled scan and applies actions to software that it detects, according to your settings; or
  • encounters an error or other problem.

  If MAPS reports new malware to Microsoft that Microsoft Security Essentials can remove, new signatures will be automatically downloaded to your computer, helping to protect your machine more rapidly from potential threats.

  Microsoft uses error reports to help Microsoft Security Essentials operate as intended—to help protect your computer against potential threats.

  You can join MAPS with a basic or an advanced membership. By default you are opted into basic membership. Basic member reports contain the information described in this section. Advanced member reports are more comprehensive and might occasionally contain personal information from, for example, file paths and partial memory dumps. These reports, along with reports from other Microsoft Security Essentials users who are participating in MAPS, help our researchers discover new threats more rapidly. Malware definitions are then created for apps that meet the analysis criteria, and the updated definitions are made available to all users through Windows Update.

  If you join MAPS with a basic or an advanced membership, Microsoft might request a sample submission report. This report contains specific files from your PC that Microsoft suspects might be potentially unwanted software. The report is used for further analysis. You will be asked each time if you want to send this sample submission report to Microsoft.

  To help protect your privacy, reports that are sent to Microsoft are encrypted.

  Use of information: MAPS reports are used to improve Microsoft software and services. The reports might also be used for statistical or other testing or analytical purposes, and for generating definitions. Only Microsoft employees, contractors, partners, and vendors who have a business need to use the reports are provided access to them. MAPS does not intentionally collect personal information. To the extent that MAPS collects any personal information, Microsoft does not use the information to identify you or contact you.

  Choice and control: You may choose your MAPS membership—basic or advanced—at any time by using the "Settings" tab in Microsoft Security Essentials. Please note that MAPS only operates if Microsoft Security Essentials has been enabled on your computer.

  When Microsoft Security Essentials is upgraded, Microsoft will honor your settings until you make a change.

  Customer Experience Improvement Program

  What This Feature Does: The Customer Experience Improvement Program (“CEIP”) collects basic information about your hardware configuration and how you use our software and services in order to identify trends and usage patterns. CEIP also collects the type and number of errors you encounter, software and hardware performance, and the speed of services. We won't collect your name, address, or other contact information.

  Information Collected, Processed, or Transmitted: For more information about the information collected, processed, or transmitted by CEIP, see the CEIP privacy statement at http://go.microsoft.com/fwlink/?LinkID=52097.

  Use of Information: We use this information to improve the quality, reliability, and performance of Microsoft software and services.

  Choice/Control: CEIP is off by default.
  You're offered the opportunity to participate in CEIP during setup.
  If you choose to participate and later change your mind, you can turn off CEIP at any time by:
  Using the CEIP Opt-out run-time dialog. From the Help menu, open the link named “Customer Experience Improvement Program” and check the ‘Don’t Join’ radio button. 

  For Windows 7/ Vista 64 Bit

  

  
  

  For Windows 7/ Vista 32 Bit

  

  
  

  For Windows XP -32 Bit
  

* Your PC must run genuine Windows to install Microsoft Security Essentials. Internet access fees may apply while downloading.