Why are my PowerShell scripts not running?

It could be PowerShell's default security level, which (IIRC) will only run signed scripts.

Try typing this:

set-executionpolicy remotesigned

That will tell PowerShell to allow local (that is, on a local drive) unsigned scripts to run.

Then try executing your script again.

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.

Use:

Set-ExecutionPolicy -ExecutionPolicy Bypass -Scope Process

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

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%

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

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.

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 -

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

It would be ideal to bypass execution policies e.g. through

powershell -executionpolicy bypass -File .\MYSCRIPT.ps1

Unfortunately this can still be prevented by group policies. As a workaround, you can encode your script as Base64 by running this in PowerShell:

[Convert]::ToBase64String([Text.Encoding]::Unicode.GetBytes((Get-Content .\MYSCRIPT.ps1)))

Then execute the result like this:

powershell.exe -EncodedCommand "put-your-base64-string-here"

Caveat: This won't work with scripts that require parameters.