Powershell - Start-Process to launch hello world is not working

Question

I am trying to figure out how to run powershell script with elevated credentials, and was told the best way to do this was with Start-Process

And this website, http://social.technet.microsoft.com/Forums/windowsserver/en-US/132e170f-e3e8-4178-9454-e37bfccd39ea/startprocess-verb-runas-credential is also good reference

But I am still having trouble.

I created one script for testing purposes, hello.ps1

write-host Hello World

That runs well by itself

Then, I created another script to invoke Hello World with elevated credentials

<#Previously created password file in C:\Script\cred.txt, read-host -assecurestring | convertfrom-securestring | out-file C:\Script\cred.txt#>

$password = get-content C:\Script\cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\Username",$password
$script = "C:\script\hello.ps1"
Start-Process powershell -Credential $credentials -verb runas -ArgumentList "-file $script"

And I get error:

At C:\script\my_script.ps1:6 char:14
+ Start-Process <<<<  powershell -Credential $credentials -verb runas -ArgumentList "-file $script"
    + CategoryInfo          : InvalidArgument: (:) [Start-Process], ParameterBindingException
    + FullyQualifiedErrorId : AmbiguousParameterSet,Microsoft.PowerShell.Commands.StartProcessCommand

EDIT

@Adi Inbar

I updated the code as follows

$password = get-content C:\Script\cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\Username",$password
$script = "C:\Script\hello.ps1"
Start-Process powershell -Credential $credentials  -ArgumentList "-file $script"

But now a cmd windows pops up and the output is blank, instead of the expected "Hello World"

EDIT

And I read that you must include -FilePath if you include -Credential, but code is still not working :-(

It just pops-up the cmd window and no output is written in powershell_ise.exe GUI

<#Previously created password file in C:\Script\cred.txt, read-host -assecurestring | convertfrom-securestring | out-file C:\Script\cred.txt#>

$password = get-content C:\Script\cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\Username",$password
$script = "C:\Script\hello.ps1"
Start-Process -FilePath C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -Credential $credentials -ArgumentList "-file $script"

Answer 1

Well, I was able to answer parts of my question, because I still have a bigger question that I will post separately

'noexit' in -ArgumentList keeps the cmd window persistent, but at least it outputs the value, so at least I know the program is working

<#Previously created password file in C:\Script\cred.txt, read-host -assecurestring | convertfrom-securestring | out-file C:\Script\cred.txt#>

$password = get-content C:\Script\cred.txt | convertto-securestring
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist "DOMAIN\Username",$password
$script = "C:\Script\hello.ps1"

start-process powershell -Credential $credentials -ArgumentList '-noexit','-File', 'C:\script\hello.ps1'