Windows Defender Definitions

What is Windows Defender?

The Windows Defender is an anti-malware tool which protects your endpoints from data theft, viruses, malware, spyware, etc. It serves as a protection tool by scanning and cleaning your computers. Let's say your entire network is relying on this protection tool and this Windows Defender software isn't updated. What happens? This tool which is supposed to safeguard your systems will not be able to completely protect them if the Windows Defender definition isn't updated regularly. We recommend you to check for updates of Windows Defender on a daily basis.

In order to keep track of the updates every day you can use any of the following methods:

  1. Manual installation of Windows Defender definitions update
  2. Automatic installation of Windows Defender definitions update
  3. Installation using the Control Panel

Manual Installation of Windows Defender definitions update:

You can install Windows Defender manually in two ways:

  1. Standard method
  2. Using Windows PowerShell
  1. Standard method:

    How to manually update Windows Defender definitions?

    • To begin with manually updating your Windows Defender, you'll have to first find out whether you're using a 32-bit or a 64-bit version of Windows 7/8.1/10.
    • The next step is to download the installer files of the Windows version which you're using. You can download them here:
      32-bit version: Windows 7 / 8 or 8.1 / 10
      64-bit version: Windows 7 / 8 or 8.1 / 10
    • Go to the downloads section and click on the downloaded file to install Windows Defender definitions. Follow the prompts given by the installation wizard to update the Windows Defender.

    This is how you install Windows Defender manually using the standard method.

  2. Using Windows PowerShell:

    How to update Windows Defender definitions using Windows PowerShell?

    • To install Windows Defender manually using Windows PowerShell, press 'Win Key + Q' and type 'Windows PowerShell'. Right-click on it and choose to 'Run as administrator'.
    • When prompted for the credentials, provide them.
    • First type 'cd..' and press the 'Enter' key. Then type 'cd..' again and press the 'Enter' key.
    • Type this command and press the 'Enter' key to update definitions.

      PS C:\> Update-MpSignature

      If you wish to update the definitions source, you should alter the command given above.

      PS C:\> Update-MpSignature -UpdateSource MicrosoftUpdateServer

      Note: The update sources which can be used are InternalDefinitionUpdateServer and Microsoft Malware Protection Center (MMPC).

Automatic installation of Windows Defender definitions update:

With a patch management tool like Patch Manager Plus you can install Windows Defender automatically by keeping track of the Definition Updates being released every now and then. It's tedious to update them frequently from the anti-virus vendors site and also consumes a lot of bandwidth. This patching tool has a feature called Automated Patch Deployment (APD) which has an option to install Windows Defender automatically.

Follow the steps given below to update the Windows Defender definitions:

  • Navigate to the Patch Manager Plus console and go to Admin -> Deployment Settings -> Automate Patch Deployment.
  • Click on Automate Task and choose the platform as Windows.
  • Give a suitable name for the APD task that you're creating using the edit option.
  • The first stage of creating this task is Select Applications. Under Anti-virus Updates select the checkbox Definition Update. On selecting this box, you'll be provided with the latest Windows Defender definition updates.

    Note: We support the following Definition Updates - Mcafee Virusscan Enterprise, Microsoft Forefront Endpoint Protection 2010 Server Management, Microsoft Forefront Endpoint Protection 2010 Server Management x64, Microsoft Forefront Client Security, Microsoft Forefront Client Security x64, Microsoft Security Essentials, Microsoft Security Essentials x64.

  • The second stage of this APD task is to choose the deployment policy wherein you can select the existing deployment policy or create a new one. So here you can configure the frequency and the preferred day for deployment to happen.
  • The third stage is where you can specify the target computers on which you want the deployment to happen.
  • The final stage is configuring notifications so that you'll be notified about the APD task. After providing your e-mail address and selecting the required options, click on Save.

So this is how you can automatically update the Windows Defender definitions. To know about how to create an Automate Patch Deployment task in detail to install Windows Defender automatically, refer to this document.

Installation using the Control Panel:

Another way of installing Windows Defender Definitions is through the Control Panel.
The steps to be followed are given below:

  • Press the 'Win key + R' -> Type 'Control Panel' -> Click on 'OK'.
  • Once the Control Panel is opened, click on System and Security -> Administrative Tools -> Task Scheduler.
  • In the Task Scheduler, towards the right under Actions click on Create Basic Task.
  • This will open the Create Basic Task Wizard. Give a suitable name and description and click on Next.
  • Choose how often you want this task to run from the options listed there and click on Next.
  • You can set the Start and End time of this task and then click on Next.
  • Choose the option Start a program.
  • Type “C:\Program Files\Windows Defender\MpCmdRun.exe” in the Program box. This executable file helps in performing tasks like scanning and updating the Windows Defender definitions.
  • Once you've entered the details and chosen all the required options, click on Finish.

Thus, the scheduled task will happen on the specified days and time which you've set. So this is how you can install the updates of Windows Defender definitions through the Control Panel.