PowerShell - how to open PowerShell as admin and launch script as admin

Question

I am struggling with a very complex problem. Application which my script must install requires elevation of admin rights. Attaching to this application is also available only for an admin. First of all, I am setting execution policy:

try
{
  Set-ExecutionPolicy -Scope CurrentUser Unrestricted
  Write-Output "Completed"
}
catch
{
 throw $PSItem
}

My next PowerShell script creates a PSCredential object with domain\user combination and password. After that, it uses the following command to open the .exe setup file:

Start-Process powershell -Credential $credential -ArgumentList ('-noprofile -command &{Start-Process "' + $filePathSetup + '" -wait -verb runas}')

and proceeds with executing installation code.

It works when I manually open PowerShell ISE with admin credentials provided and paste my script. However, in practice I am running my scripts from external software (Blue Prism) and I can neither use GUI nor perform manual activities. Application needs to be installed without any human interruption, entirely programmatically, so I cannot open PowerShell as admin on my own.

What am I doing instead? I create a Runspace and a PowerShell Object, add my script which installs the app to this PowerShell Object and invoke it this way:

Runspace runspace;

try {

  runspace = RunspaceFactory.CreateRunspace();
  if(STA == true) {
    runspace.ApartmentState = System.Threading.ApartmentState.STA;
  } else {
    runspace.ApartmentState = System.Threading.ApartmentState.MTA;
  }
  runspace.ThreadOptions = PSThreadOptions.ReuseThread;
  runspace.Open();

} catch(System.Exception ex) {
  ErrorMessage = ex.Message;
  return;
}

//-Create PowerShell----------------------------------------------------
System.Management.Automation.PowerShell PS;

try {

  PS = System.Management.Automation.PowerShell.Create();
  PS.Runspace = runspace;
  PS.AddScript(PSCode);

} catch(System.Exception ex) {
  runspace.Close();
  ErrorMessage = ex.Message;
  return;
}

//-Add parameters to PowerShell-----------------------------------------
    foreach(DataRow ThisRow in Parameters.Rows) {
        PS.AddParameter(ThisRow["Name"].ToString().Trim(), ThisRow["Value"].ToString().Trim());
  }

//-Invoke PowerShell----------------------------------------------------
try {

  Collection<PSObject> Ret = PS.Invoke();
  runspace.Close();

And what is my problem? I cannot switch to admin within this code, but it is required for me to run both PowerShell & the application as admin whereas now I am only running the app as admin via PowerShell. I heard of an old Impersonate class which would be helpful but it is no longer supported. What would you suggest me to do?

PS No manual actions please. I know how to press right mouse button to open contextual menu and select Run as Admin ;)

Answer 1

Not sure what the issue here is but we do something at startup across all BP machines that requires admin privileges. To do this we set a task in task scheduler to 'run with highest privileges' whether 'user is logged in or not' then that task will fire a cmd script which points to our powershell files and they all run fine without admin prompts. Task scheduler requests the admin credentials on the machine during task config but I think that would solve what you're attempting here.