Set-ExecutionPolicy

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 in the order of precedence, 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 provider 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.

PS> 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

-ExecutionPolicy

-Force

-Scope

-WhatIf

Inputs

Microsoft.PowerShell.ExecutionPolicy, System.String

You can pipe an execution policy object or a string that contains the name of an execution policy to Set-ExecutionPolicy.

Outputs

None

Set-ExecutionPolicy doesn't return any 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 is not effective. PowerShell displays a message that explains the conflict.

Related Links

• about_Execution_Policies
• about_Group_Policy_Settings
• about_Providers
• Get-AuthenticodeSignature
• Get-ChildItem
• Get-ExecutionPolicy
• Invoke-Command
• Set-AuthenticodeSignature
• Unblock-File