Networking / Security · Risk: High · Documentation Verified
Last verified: 2026-10-26
Microsoft Defender reference: Modifies settings for Windows Defender. The syntax and selected example below are adapted from the pinned Windows Server 2025 reference. Module availability, target configuration and delegated permissions determine whether it can run in your environment. Documentation and parameter text: Microsoft, CC BY 4.0; formatting adapted by Cmdlet World. No execution testing is claimed.
Use an account with the target resource permissions documented for Add-MpPreference. Modifying administrative cmdlets may require elevation or delegated administration. This catalog does not assert that ordinary users can execute the command.
Supported environments
Windows / Defender · Windows Server 2025 documentation; feature/module prerequisites apply
Parameters
-AsJob
Runs the cmdlet as a background job. Use this parameter to run commands that take a long time to complete. The cmdlet immediately returns an object that represents the job and then displays the command prompt. You can continue to work in the session while the job completes. To manage the job, use the *-Job cmdlets. To get the job results, use the Receive-Job cmdlet. For more information about Windows PowerShell background jobs, see about_Jobs.
-AttackSurfaceReductionOnlyExclusions
Specifies the files and paths to exclude from attack surface reduction (ASR) rules. Specifies the folders or files and resources that should be excluded from ASR rules. Enter a folder path or a fully qualified resource name. For example, C:\Windows excludes all files in that directory. C:\Windows\App.exe excludes only that specific file in that specific folder. See the ASR rules topic for more information about excluding files and folders from ASR rules.
-AttackSurfaceReductionRules_Actions
Specifies the states of attack surface reduction rules specified by using the AttackSurfaceReductionRules_Ids parameter. If you add multiple rules as a comma-separated list, specify their states separately as a comma-separated list.
-AttackSurfaceReductionRules_Ids
Specifies the IDs of attack surface reduction rules. Use the AttackSurfaceReductionRules_Actions parameter to specify the state for each rule. If you add multiple rules as a comma-separated list, specify their states separately as a comma-separated list.
-CimSession
Runs the cmdlet in a remote session or on a remote computer. Enter a computer name or a session object, such as the output of a New-CimSession or Get-CimSession cmdlet. The default is the current session on the local computer.
-ControlledFolderAccessAllowedApplications
Specifies applications that can make changes in controlled folders.
-ControlledFolderAccessProtectedFolders
Specifies more folders to protect.
-ExclusionExtension
Specifies an array of file name extensions, such as obj or lib, to exclude from scheduled, custom, and real-time scanning. This cmdlet adds these file name extensions to the exclusions.
-ExclusionIpAddress
Specifies an array of IP addresses to exclude from scheduled and real-time scanning.
-ExclusionPath
Specifies an array of file paths to exclude from scheduled and real-time scanning. You can specify a folder to exclude all the files under the folder.
-ExclusionProcess
Specifies an array of processes, as paths to process images. This cmdlet excludes any files opened by the processes that you specify from scheduled and real-time scanning. Specifying this parameter excludes files opened by executable programs only. The cmdlet does not exclude the processes themselves. To exclude a process, specify it by using the ExclusionPath parameter.
-Force
Forces the command to run without asking for user confirmation.
-ThreatIDDefaultAction_Actions
Specifies an array of the actions to take for the IDs specified by using the ThreatIDDefaultAction_Ids parameter. The acceptable values for this parameter are: - 1: Clean - 2: Quarantine - 3: Remove - 6: Allow - 8: UserDefined - 9: NoAction - 10: Block
-ThreatIDDefaultAction_Ids
Specifies an array of threat IDs. This cmdlet adds the default action for the threat IDs that you specify.
-ThrottleLimit
Specifies the maximum number of concurrent operations that can be established to run the cmdlet. If this parameter is omitted or a value of 0 is entered, then Windows PowerShell® calculates an optimum throttle limit for the cmdlet based on the number of CIM cmdlets that are running on the computer. The throttle limit applies only to the current cmdlet, not to the session or to the computer.
Prerequisites
Windows with the Defender module and the Windows feature or management tools that provide it. Confirm target connectivity and version compatibility using the linked Microsoft reference.
Security considerations
This cmdlet changes system state. Review every target and parameter in the official reference, test outside production, and prepare an appropriate backup or rollback. Do not execute the example automatically.
Examples
Example 1: Add a folder to the exclusion list
Add-MpPreference -ExclusionPath 'C:\Temp'
This command adds the folder C:\Temp to the exclusion list. The command disables Windows Defender scheduled and real-time scanning for files in this folder. Source: Microsoft, CC BY 4.0; transcript prompt/output removed. This example was not executed.