How to enable execution of PowerShell scripts?

1. Start Windows PowerShell with the "Run as Administrator" option. Only members of the Administrators group on the computer can change the execution policy.

2. Enable running unsigned scripts by entering:

   set-executionpolicy remotesigned
   

This will allow running unsigned scripts that you write on your local computer and signed scripts from Internet.

See also Running Scripts at Microsoft TechNet Library.

The Default Execution Policy is set to restricted, you can see it by running Get-ExecutionPolicy:

Get-ExecutionPolicy

Run Set-ExecutionPolicy like this to switch to the unrestricted mode:

Set-ExecutionPolicy unrestricted

On my machine that I use to dev scripts, I will use -unrestricted as above. When deploying my scripts however, to an end user machine, I will just call powershell with the -executionpolicy switch:

powershell.exe -noprofile -executionpolicy bypass -file .\script.ps1

We can get the status of current ExecutionPolicy by the command below:

Get-ExecutionPolicy;

By default it is Restricted. To allow the execution of PowerShell Scripts we need to set this ExecutionPolicy either as Bypass or Unrestricted.

We can set the policy for Current User as Bypass or Unrestricted by using any of the below PowerShell command:

Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy Bypass -Force;

Set-ExecutionPolicy -Scope CurrentUser -ExecutionPolicy Unrestricted -Force;

Unrestricted policy loads all configuration files and runs all scripts. If you run an unsigned script that was downloaded from the Internet, you are prompted for permission before it runs.

Whereas in Bypass policy, nothing is blocked and there are no warnings or prompts during script execution. Bypass ExecutionPolicy is more relaxed than Unrestricted.

Depending on the Windows version and configuration, you may have the following warning, even in Unrestricted mode:

Security warning
Run only scripts that you trust. While scripts from the internet can be useful, this
script can potentially harm your computer. If you trust this script, use the 
Unblock-File cmdlet to allow the script to run without this warning message. 
Do you want to run?
[D] Do not run  [R] Run once  [S] Suspend  [?] Help (default is "D")

The solution is to use the "bypass" policy, enabled with the following command:

Set-ExecutionPolicy Bypass

From the documentation:

Bypass: Nothing is blocked and there are no warnings or prompts.

This is obviously insecure, please understand the risks involved.