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Set-ExecutionPolicy

  • Reference
Module:
Microsoft.PowerShell.Security

Sets the PowerShell execution policies for Windows computers.

Syntax

Set-ExecutionPolicy
   [-ExecutionPolicy] <ExecutionPolicy>
   [[-Scope] <ExecutionPolicyScope>]
   [-Force]
   [-WhatIf]
   [-Confirm]
   [<CommonParameters>]

Description

The Set-ExecutionPolicy cmdlet changes PowerShell execution policies for Windows computers. For more information, see about_Execution_Policies.

An execution policy is part of the PowerShell security strategy. Execution policies determine whether you can load configuration files, such as your PowerShell profile, or run scripts. And, whether scripts must be digitally signed before they are run.

The Set-ExecutionPolicy cmdlet's default scope is LocalMachine, which affects everyone who uses the computer. To change the execution policy for LocalMachine, start PowerShell with Run as Administrator.

To display the execution policies for each scope, use Get-ExecutionPolicy -List. To see the effective execution policy for your PowerShell session use Get-ExecutionPolicy with no parameters.

Examples

Example 1: Set an execution policy

This example shows how to set the execution policy for the local computer.

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine
Get-ExecutionPolicy -List

Scope ExecutionPolicy
        ----- ---------------
MachinePolicy       Undefined
   UserPolicy       Undefined
      Process       Undefined
  CurrentUser    RemoteSigned
 LocalMachine    RemoteSigned

The Set-ExecutionPolicy cmdlet uses the ExecutionPolicy parameter to specify the RemoteSigned policy. The Scope parameter specifies the default scope value, LocalMachine. To view the execution policy settings, use the Get-ExecutionPolicy cmdlet with the List parameter.

Example 2: Set an execution policy that conflicts with a Group Policy

This command attempts to set the LocalMachine scope's execution policy to Restricted. LocalMachine is more restrictive, but isn't the effective policy because it conflicts with a Group Policy. The Restricted policy is written to the registry hive HKEY_LOCAL_MACHINE.

PS> Set-ExecutionPolicy -ExecutionPolicy Restricted -Scope LocalMachine

Set-ExecutionPolicy : PowerShell updated your local preference successfully, but the setting is
overridden by the Group Policy applied to your system. Due to the override, your shell will retain
its current effective execution policy of "AllSigned". Contact your Group Policy administrator for
more information. At line:1 char:20 + Set-ExecutionPolicy <<<< restricted

PS> Get-ChildItem -Path HKLM:\SOFTWARE\Microsoft\PowerShell\1\ShellIds

    Hive: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds

Name                    Property
----                    --------
Microsoft.PowerShell    Path            : C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
                        ExecutionPolicy : Restricted
ScriptedDiagnostics     ExecutionPolicy : Unrestricted

The Set-ExecutionPolicy cmdlet uses the ExecutionPolicy parameter to specify the Restricted policy. The Scope parameter specifies the default scope value, LocalMachine. The Get-ChildItem cmdlet uses the Path parameter with the HKLM: drive to specify registry location.

Example 3: Apply the execution policy from a remote computer to a local computer

This command gets the execution policy object from a remote computer and sets the policy on the local computer. Get-ExecutionPolicy sends a Microsoft.PowerShell.ExecutionPolicy object down the pipeline. Set-ExecutionPolicy accepts pipeline input and doesn't require the ExecutionPolicy parameter.

Invoke-Command -ComputerName Server01 -ScriptBlock { Get-ExecutionPolicy } | Set-ExecutionPolicy

The Invoke-Command cmdlet is executed at the local computer and sends the ScriptBlock to the remote computer. The ComputerName parameter specifies the remote computer, Server01. The ScriptBlock parameter runs Get-ExecutionPolicy on the remote computer. The Get-ExecutionPolicy object is sent down the pipeline to the Set-ExecutionPolicy. Set-ExecutionPolicy applies the execution policy to the local computer's default scope, LocalMachine.

Example 4: Set the scope for an execution policy

This example shows how to set an execution policy for a specified scope, CurrentUser. The CurrentUser scope only affects the user who sets this scope.

Set-ExecutionPolicy -ExecutionPolicy AllSigned -Scope CurrentUser
Get-ExecutionPolicy -List

Scope ExecutionPolicy
        ----- ---------------
MachinePolicy       Undefined
   UserPolicy       Undefined
      Process       Undefined
  CurrentUser       AllSigned
 LocalMachine    RemoteSigned

Set-ExecutionPolicy uses the ExecutionPolicy parameter to specify the AllSigned policy. The Scope parameter specifies the CurrentUser. To view the execution policy settings, use the Get-ExecutionPolicy cmdlet with the List parameter.

The effective execution policy for the user becomes AllSigned.

Example 5: Remove the execution policy for the current user

This example shows how use the Undefined execution policy to remove an execution policy for a specified scope.

Set-ExecutionPolicy -ExecutionPolicy Undefined -Scope CurrentUser
Get-ExecutionPolicy -List

Scope ExecutionPolicy
        ----- ---------------
MachinePolicy       Undefined
   UserPolicy       Undefined
      Process       Undefined
  CurrentUser       Undefined
 LocalMachine    RemoteSigned

Set-ExecutionPolicy uses the ExecutionPolicy parameter to specify the Undefined policy. The Scope parameter specifies the CurrentUser. To view the execution policy settings, use the Get-ExecutionPolicy cmdlet with the List parameter.

Example 6: Set the execution policy for the current PowerShell session

The Process scope only affects the current PowerShell session. The execution policy is saved in the environment variable $env:PSExecutionPolicyPreference and is deleted when the session is closed.

Set-ExecutionPolicy -ExecutionPolicy AllSigned -Scope Process

Scope ExecutionPolicy
        ----- ---------------
MachinePolicy       Undefined
   UserPolicy       Undefined
      Process       AllSigned
  CurrentUser    RemoteSigned
 LocalMachine    RemoteSigned

The Set-ExecutionPolicy uses the ExecutionPolicy parameter to specify the AllSigned policy. The Scope parameter specifies the value Process. To view the execution policy settings, use the Get-ExecutionPolicy cmdlet with the List parameter.

Example 7: Unblock a script to run it without changing the execution policy

This example shows how the RemoteSigned execution policy prevents you from running unsigned scripts.

A best practice is to read the script's code and verify it's safe before using the Unblock-File cmdlet. The Unblock-File cmdlet unblocks scripts so they can run, but doesn't change the execution policy.

PS> Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope LocalMachine

PS> Get-ExecutionPolicy

RemoteSigned

PS> .\Start-ActivityTracker.ps1

.\Start-ActivityTracker.ps1 : File .\Start-ActivityTracker.ps1 cannot be loaded.
The file .\Start-ActivityTracker.ps1 is not digitally signed.
The script will not execute on the system.
For more information, see about_Execution_Policies at https://go.microsoft.com/fwlink/?LinkID=135170.
At line:1 char:1
+ .\Start-ActivityTracker.ps1
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : NotSpecified: (:) [], PSSecurityException
+ FullyQualifiedErrorId : UnauthorizedAccess

PS> Unblock-File -Path .\Start-ActivityTracker.ps1

PS> Get-ExecutionPolicy

RemoteSigned

PS> .\Start-ActivityTracker.ps1

Task 1:

The Set-ExecutionPolicy uses the ExecutionPolicy parameter to specify the RemoteSigned policy. The policy is set for the default scope, LocalMachine.

The Get-ExecutionPolicy cmdlet shows that RemoteSigned is the effective execution policy for the current PowerShell session.

The Start-ActivityTracker.ps1 script is executed from the current directory. The script is blocked by RemoteSigned` because the script isn't digitally signed.

For this example, the script's code was reviewed and verified as safe to run. The Unblock-File cmdlet uses the Path parameter to unblock the script.

To verify that Unblock-File didn't change the execution policy, Get-ExecutionPolicy displays the effective execution policy, RemoteSigned.

The script, Start-ActivityTracker.ps1 is executed from the current directory. The script begins to run because it was unblocked by the Unblock-File cmdlet.

Parameters

-Confirm

Prompts you for confirmation before running the cmdlet.

Type:SwitchParameter
Aliases:cf
Position:Named
Default value:False
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-ExecutionPolicy

Specifies the execution policy. If there are no Group Policies and each scope's execution policy is set to Undefined, then Restricted becomes the effective policy for all users.

The acceptable execution policy values are as follows:

  • AllSigned. Requires that all scripts and configuration files are signed by a trusted publisher, including scripts written on the local computer.
  • Bypass. Nothing is blocked and there are no warnings or prompts.
  • Default. Sets the default execution policy. Restricted for Windows clients or RemoteSigned for Windows servers.
  • RemoteSigned. Requires that all scripts and configuration files downloaded from the Internet are signed by a trusted publisher. The default execution policy for Windows server computers.
  • Restricted. Doesn't load configuration files or run scripts. The default execution policy for Windows client computers.
  • Undefined. No execution policy is set for the scope. Removes an assigned execution policy from a scope that is not set by a Group Policy. If the execution policy in all scopes is Undefined, the effective execution policy is Restricted.
  • Unrestricted. Loads all configuration files and runs all scripts. If you run an unsigned script that was downloaded from the internet, you're prompted for permission before it runs.
Type:ExecutionPolicy
Accepted values:AllSigned, Bypass, Default, RemoteSigned, Restricted, Undefined, Unrestricted
Position:0
Default value:None
Required:True
Accept pipeline input:True
Accept wildcard characters:False

-Force

Suppresses all the confirmation prompts. Use caution with this parameter to avoid unexpected results.

Type:SwitchParameter
Position:Named
Default value:False
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Scope

Specifies the scope that is affected by an execution policy. The default scope is LocalMachine.

The effective execution policy is determined by the order of precedence as follows:

  • MachinePolicy - Set by a Group Policy for all users of the computer
  • UserPolicy - Set by a Group Policy for the current user of the computer
  • Process - Affects only the current PowerShell session
  • LocalMachine - Default scope that affects all users of the computer
  • CurrentUser - Affects only the current user

The Process scope only affects the current PowerShell session. The execution policy is saved in the environment variable $env:PSExecutionPolicyPreference, rather than the registry. When the PowerShell session is closed, the variable and value are deleted.

Execution policies for the CurrentUser scope are written to the registry hive HKEY_LOCAL_USER.

Execution policies for the LocalMachine scope are written to the registry hive HKEY_LOCAL_MACHINE.

Type:ExecutionPolicyScope
Accepted values:CurrentUser, LocalMachine, MachinePolicy, Process, UserPolicy
Position:1
Default value:LocalMachine
Required:False
Accept pipeline input:True
Accept wildcard characters:False

-WhatIf

Shows what would happen if the cmdlet runs. The cmdlet is not run.

Type:SwitchParameter
Aliases:wi
Position:Named
Default value:False
Required:False
Accept pipeline input:False
Accept wildcard characters:False

Inputs

ExecutionPolicy

You can pipe an execution policy object to this cmdlet.

String

You can pipe a string that contains the name of an execution policy to this cmdlet.

Outputs

None

This cmdlet returns no output.

Notes

Set-ExecutionPolicy doesn't change the MachinePolicy and UserPolicy scopes because they are set by Group Policies.

Set-ExecutionPolicy doesn't override a Group Policy, even if the user preference is more restrictive than the policy.

If the Group Policy Turn on Script Execution is enabled for the computer or user, the user preference is saved, but it's not effective. PowerShell displays a message that explains the conflict.