PowerShell: Update Scheduled Task username and password? - powershell

Question

I'm looking for a way to update the credentials on existing scheduled tasks on machines.
Schtasks doesn't work for AT created scheduled tasks
Win32_ScheduledJob only works for AT created jobs
Schedule.Service COM object - not sure
It appears that I can use RegisterTask and RegisterTaskDefinition to CREATE scheduled tasks but I'm not clear if I can update the existing credentials with those methods. Please advise. Thx.

Answer 1

I would recommend having a look at the managed TaskScheduler API, which is a .NET wrapper for the TaskScheduler COM API. It's an open-source project available on CodePlex.
http://taskscheduler.codeplex.com/
The project author has this to say about updating passwords:
If you are trying to create a task using the credentials of the
current user and you only want it to run when that user is logged in,
you need to call the RegisterTaskDefinition method as in the end of
the Complex example with the InteractiveToken parameter. If you need
to create as another specific user, then use that same method, but
supply the username, password, and set the TaskLogonType to
InteractiveTokenOrPassword or Password. There are some triggers that
are specific to a user, like the LogonTrigger where you can also
supply a user credential.
The appropriate overload for RegisterTaskDefinition is defined in TaskFolder.cs.
http://taskscheduler.codeplex.com/SourceControl/changeset/view/75611#19440
public Task RegisterTaskDefinition(string Path, TaskDefinition definition
, TaskCreation createType, string UserId, string password = null
, TaskLogonType LogonType = TaskLogonType.S4U, string sddl = null)

Answer 2

I had this task come up recently. I know this post is old but wanted to put this script somewhere for people to find hopefully help them. This is pure power shell so no extra setup required. I had tried using the Set-ScheduledTask but had issues setting domain user. I ended up using schtasks instead. You may need to run this script as administrator.
$domainUsername = "domain\user"
$password= "somePassword"
$tasks = Get-ScheduledTask | Where-Object { $_.Principal.UserId -eq $domainUsername }
foreach ($task in $tasks) {
$myTask = $task.TaskPath+$task.TaskName
echo changing $myTask
schtasks /change /s $env:COMPUTERNAME /tn $myTask /ru $domainUsername /rp $password
}
Here is another example of how to push out to multiple servers. THe sessionCredentials are the credentials used to connect to the servers the domain user and new password are the name and password to be set to the tasks
$sessionCredentials = Get-Credential
$taskDomainUsername = "DOMAIN\SOMEACCOUNT"
$NewPassword = "somePassword"
$computerNames = #(
"someNameServer1",
"someNameServer2"
)
$serverSession = New-CimSession -ComputerName $computerNames -Credential $sessionCredentials
$tasks = Get-ScheduledTask -CimSession $serverSession | Where-Object { $_.Principal.UserId -eq $taskDomainUsername }
foreach($task in $tasks) {
echo updating $task
$specificSession = $serverSession | Where-Object { $_.ComputerName -eq $task.PSComputerName}
$taskFullName = $task.TaskPath+$task.TaskName
Set-ScheduledTask -CimSession $specificSession -TaskName $taskFullName -User $taskDomainUsername -Password $NewPassword
}