[powershell] Why are my PowerShell scripts not running?

I wrote a simple batch file as a PowerShell script, and I am getting errors when they run.

It's in a scripts directory in my path. This is the error I get:

Cannot be loaded because the execution of scripts is disabled on this system. Please see "get-help about-signing".

I looked in the help, but it's less than helpful.

The command set-executionpolicy unrestricted will allow any script you create to run as the logged in user. Just be sure to set the executionpolicy setting back to signed using the set-executionpolicy signed command prior to logging out.

You need to run Set-ExecutionPolicy:

Set-ExecutionPolicy Restricted <-- Will not allow any powershell scripts to run.  Only individual commands may be run.

Set-ExecutionPolicy AllSigned <-- Will allow signed powershell scripts to run.

Set-ExecutionPolicy RemoteSigned <-- Allows unsigned local script and signed remote powershell scripts to run.

Set-ExecutionPolicy Unrestricted <-- Will allow unsigned powershell scripts to run.  Warns before running downloaded scripts.

Set-ExecutionPolicy Bypass <-- Nothing is blocked and there are no warnings or prompts.

On Windows 10: Click change security property of myfile.ps1 and change "allow access" by right click / properties on myfile.ps1

Use:

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process

Always use the above command to enable to executing PowerShell in the current session.

We can bypass execution policy in a nice way (inside command prompt):

type file.ps1 | powershell -command -

Or inside powershell:

gc file.ps1|powershell -c -

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process

The above command worked for me even when the following error happens:

Access to the registry key 'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\1\ShellIds\Microsoft.PowerShell' is denied.

Also it's worth knowing that you may need to include .\ in front of the script name. For example:

.\scriptname.ps1

import-module IISAdministration;

function StartSite{
    param($sitename)
    try{
        Start-IISSite -Name $sitename;
        Write-Host "Site was started";
    }
    catch{
        Write-Error "Error while staring the IISSite";
    }
}

function StopSite{
    param($sitename)
    try{
        Stop-IISSite -Name $sitename -confirm:$False; # Supress interaction inputs
        Write-Host "Site was stopped";
    }
    catch{
            Write-Error "Error while stopping the IISSite";
    }
}
function ReplaceSiteFiles{
    try{
        Get-ChildItem -Path A:\APPS\CreditApp -Recurse | Foreach-Object {Remove-Item -Recurse -Path $_.FullName} # Remove file from AppPool Directory
        Expand-Archive A:\Staging\LTA\Installers\CreditApp\CreditApp.zip -DestinationPath A:\APPS\ # Extract files from zip
        Write-Host "Site files replaced successfully!";
    }
    catch [System.SystemException]{
        Write-Host "Error while replacing the site files";
        Write-Host $_
    }
}

## Start Here
$site=Get-IISSite -Name "Default Web Site";

Write-Host $site

if($site.length -eq 1){

    $siteState = $site.state;
    Write-Host "The Site Exists with state: ${siteState}";

    switch ($siteState)
    {
        'started' { 
                    StopSite -sitename $site.name;
                    ReplaceSiteFiles;
                    StartSite -sitename $site.name;
                    
                  }
        'stopped' { 
                    ReplaceSiteFiles;
                    StartSite -sitename $site.name;
                  }
        default { "Deployment failed! Site state could not be determined.";}
    }    
}

else{
    Write-Error "Invalid! Site does not exists";
}

##  End Here

I was able to bypass this error by invoking PowerShell like this:

powershell -executionpolicy bypass -File .\MYSCRIPT.ps1

That is, I added the -executionpolicy bypass to the way I invoked the script.

This worked on Windows 7 Service Pack 1. I am new to PowerShell, so there could be caveats to doing that that I am not aware of.

[Edit 2017-06-26] I have continued to use this technique on other systems including Windows 10 and Windows 2012 R2 without issue.

Here is what I am using now. This keeps me from accidentally running the script by clicking on it. When I run it in the scheduler I add one argument: "scheduler" and that bypasses the prompt.

This also pauses the window at the end so I can see the output of PowerShell.

if NOT "%1" == "scheduler" (
   @echo looks like you started the script by clicking on it.
   @echo press space to continue or control C to exit.
   pause
)

C:
cd \Scripts

powershell -executionpolicy bypass -File .\rundps.ps1

set psexitcode=%errorlevel%

if NOT "%1" == "scheduler" (
   @echo Powershell finished.  Press space to exit.
   pause
)

exit /b %psexitcode%