Powershell - Create Scheduled Task to run as local system / service

Question

Can anyone tell me how to create a scheduled task using powershell that runs as the local system or local service?

Everything works great except the call to ITaskFolder.RegisterTaskDefinition().

If I pass in $null, or "", than the call bombs saying invalid username or password. Any thoughts"

$Rootfolder.RegisterTaskDefinition("Test", $Taskdef, 6, "LOCAL SERVICE", "", 3)

Answer 1

For those who can use PowerShell 3.0 on Windows 8 or Windows Server 2012, new cmdlets will let you do it in a simple way when registering your scheduled task with the cmdlet Register-ScheduledTask and as argument -User "System"

Here is a scheduled task created entirely with PS, its purpose is to restart a service My Service, using the SYSTEM account, 3 minutes after the system has started:

$taskname = "Restart My Service"
$taskdescription = "Restart My Service after startup"
$action = New-ScheduledTaskAction -Execute 'Powershell.exe' `
  -Argument '-NoProfile -WindowStyle Hidden -command "& Restart-Service -displayname \"My Service\""'
$trigger =  New-ScheduledTaskTrigger -AtStartup -RandomDelay (New-TimeSpan -minutes 3)
$settings = New-ScheduledTaskSettingsSet -ExecutionTimeLimit (New-TimeSpan -Minutes 2) -RestartCount 3 -RestartInterval (New-TimeSpan -Minutes 1)
Register-ScheduledTask -Action $action -Trigger $trigger -TaskName $taskname -Description $taskdescription -Settings $settings -User "System"

NB: you will need to run powershell as an administrator for that script.

Answer 2

I think you would need to use "nt authority\localservice" as the user name.

Kindness,

Dan

Answer 3

This code snippet will use the PowerShellPack's Task Scheduler module to schedule a task to run as SYSTEM immediately:

New-Task |
    ForEach-Object {
        $_.Principal.Id = "NTAuthority\SYSTEM"
        $_.Principal.RunLevel = 1
        $_
    } |
    Add-TaskAction -Script {
        "SystemTask" > C:\myTest.txt
    } |
    Add-TaskTrigger -OnRegistration |
    Register-ScheduledTask SystemTask