Microsoft Security Essentials Installation Checklist

Technical Level : Basic

This document is intended for assisting those using Microsoft Security Essentials (MSE) on Windows XP, Windows Vista, and Windows 7. Following the provided steps will not insure 100% success. There may be problems. If there are problems, return to this forum and state your Operating System and Service Pack, any previous anti-malware that you had, and what problem or error code you are experiencing.

Microsoft Security Essentials (MSE) is a free, comprehensive, anti-malware product from Microsoft.

·         It has some minimum requirements for installation. Note: You must have Windows 7/Vista (32 or 64-bit). Windows XP 32-bit is also supported. MSE does not run on any server product(s) (including Windows Home Server), nor does it run on XP 64-bit.

·         There are license requirements. Note: MSE is for home use, and for small businesses with 10 or fewer PCs.

·         You must be genuine windows.

Note that MSE is not compatible with Windows 8. Windows Defender, on Windows 8, provides the same comprehensive protection as MSE on Windows 7.

To begin the installation process, follow these steps. If you already have a backup, and your PC is already up-to-date, then you may begin at step #3.

1.       Backup your data. Use whatever media you have at your disposal to get a backup (i.e. USB stick, CD/DVD, external hard drive). After the backup, remove/unplug the media and store for safekeeping.

2.       Update your PC. You should be at the latest Service Pack for your OS, and fully updated, including optional and .NET updates. This should be done regardless of which anti-malware product you use. Being up-to-date will ensure performance, stability, and will correct known security problems. Go to Microsoft Update. If you are severely out-of-date, this can take some time. This is also a good time to check the date and time on your PC clock, and correct if necessary, and to update third-party products and drivers (Java, Adobe Flash, Adobe Reader, etc.)

3.       Remove ALL other anti-virus applications & security suites that were ever installed on your PC (Norton, McAfee, TM, AVG, Avast, Avira, ESET, etc.) Uninstall your previous real-time anti-malware. Then, use the removal/cleanup tools in this article. Not only should you remove your current anti-virus applications & security suites , you should also uninstall any free or trial anti-malware products that may have been installed on your PC when purchased, even if never activated. Some anti-malware products have their own firewall. Removing/uninstalling these products will (or should) enable the Windows Firewall. MSE will use the Windows Firewall by default. After removal and cleanup of all other anti-malware products, restart your PC and check that the Windows Firewall is ON. You can check the status of the Windows Firewall in the Action Center (or Security Center if XP) of your PC, or via the Control Panel.

4.       Install MSE. Do NOT use any site other than Microsoft to get the download. Using Internet Explorer (or Firefox), go to the MSE Download page and click the Download Now button. If you are Windows 7/Vista 64-bit, you may want to avoid any issues and click on “Available in 33 languages ” and select the 64-bit download for Windows 7/Vista. Take the default answers, including the question about turning ON the firewall, unless you specifically do not want to run a firewall.

5.       After the installation, MSE will want to update the definition files, and run a quick scan. This will not take long (except for dial-up), and needs to be done. If a virus is detected during the scan, let MSE take the default actions to correct it.

At this point, you are running MSE. There may be some background activity, but this should not interfere with your normal use of the PC. Just let it occur, and it will not take long.

MSE is always working to protect you. It will update periodically with new virus definition files, and it will perform a scheduled scan at 02:00 Sunday morning (by default). You can change the scheduled scan by opening MSE, click on the Settings tab, and select “Scheduled Scan”.

Following the above steps will not insure 100% success. There may be problems. If there are problems, return to this forum and state your OS and Service Pack, any previous anti-malware that you had, and what problem or error code you are experiencing.

Common issues that can affect MSE

Most issues with MSE installation and performance can be corrected by following the steps below:

  • Verify that you have removed all other anti-virus applications & security suites that were ever installed on your PC, including any free/trial products that were installed when the PC was purchased (Norton, McAfee, TM, AVG, Malwarebytes (paid), etc.).  Then, use the removal/cleanup tools in this article.
  • If you have installed Adobe Flash, Adobe Reader, Java, or any other “free” product, you may have been presented with the option to install a “free virus checker”, which is selected by default.  If you were caught by this, and unknowingly/accidently installed this “free virus checker”, uninstall it and use the cleanup tool(s) in the list above.  Note that these “free” downloads can also occur in products purchased by you.  Your ISP may also provide an anti-malware product (and perhaps a firewall).  Install these products ONLY if you do not intend to use MSE and/or the Windows Firewall.
  • Verify that your PC clock is correctly set.  If not, correct it.
  • Verify that Windows Defender is disabled (if Windows 7/Vista), or uninstalled (if XP),
  • Verify that you are up-to-date with the latest Service Pack and updates (including .NET).  Yes, it can take some time to do this.
  • Verify that the Windows Firewall is on, and set to defaults.
  • Verify that you are using current version of MSE.  Open MSE and click on the “down pointer” to the right of “Help”.  Then, click on “About Security Essentials”.  Provide this information when asking a question in the MSE community forum.
  • Remove ZoneAlarm firewall if you have it and use the Windows Firewall.
  • Verify that you are not using a proxy server. If you are, see: Updating Microsoft Security Essentials through a Proxy Server
  • Verify that you have “install updates automatically” selected in Windows Update (even though the MSE definition updates are optional).
  • In Internet Explorer, reset all security zones to default level.

Then, restart your PC.

You may need to remove and reinstall MSE as well.

Special thanks to the following contributors to this article:

Dr. Strangelove



See Also:

How do I uninstall antivirus or antispyware programs?

List of anti-malware product removal tools

I can't install Microsoft Security Essentials

Getting started with Microsoft Security Essentials

Fix Microsoft Windows Update Issues

Updating Microsoft Security Essentials through a Proxy Server

Microsoft Security Essentials Consolidated FAQ


Forum Article Info

Last updated June 22, 2019 Views 57,924 Applies to:
Looks promising.  I will try to do as recommended.  Thanks.

AFTER 2 YEARS and countless hours I finally got MSE to reinstall on my Dell PC that runs Windows Vista...there were several error codes along the way, the last of which was 0x80070643.  I did everything mentioned above.  Ran all the antivirus cleanups, got rid of malware/adware, fully uninstalled MSE & Windows Live by using FixItInstallUninstall wizard, double checked the clock, etc.  Updated Internet Explorer and tried again using the 2011 MSEinstall.exe (v2.0.657.0).  


But guess what, it didn't work if Internet Explorer wasn't kept open.  (We use Chrome, not IE) and I discovered quite by accident that closing IE stopped the download (network) connection.  IE doesn't open automatically when I run MSE install or updates, I have to manually open it.  I have read tons of MSE error message forum answers and didn't see any that mentioned this "minor" detail.  Hope this helps.