PowerShell script lacks consistency when run through task scheduler, am I missing something or is this Windows being Windows?

Question

I am a beginner in PowerShell.

I have created myself a PowerShell program to act as my alarm clock in the morning. I have task scheduler executing it on a time trigger. The problem i am having is a lack of consistency. Sometimes it will run properly without any interference, other times it will open PowerShell, error out and close immediately without executing (no error code). When i execute it myself with a double click, it seems to work just fine.

Execution Policy = All-Signed

Task Scheduler

Trigger Tab:

Trigger: Daily
Details: At 8:00 AM every Day
Status: Enabled

Action Tab:

Action: Start a Program
Program/Script: PowerShell.exe 
Add arguments: -NoExit D:\Programs\AlarmClock\AlarmClockScript.ps1

Script:

#define loop start state

$Snoozevar = 'Yes' 

#Import form module (for menu)

[reflection.assembly]::LoadWithPartialName("System.Windows.forms") | Out-Null

#Menu

    $snoozeTxtBox = New-Object System.Windows.Forms.Button
    $snoozeTxtBox.Text = 'Snooze'
    $snoozeTxtBox.Location = '50,15'
    $snoozeTxtBox.Size = '60,23'
    $snoozeTxtBox.DialogResult = [System.Windows.Forms.DialogResult]::Yes  # 'Snooze' = Yes

    $quitTxtBox = New-Object System.Windows.Forms.Button
    $quitTxtBox.Text = 'I`m Up'
    $quitTxtBox.Location = '125,15'
    $quitTxtBox.Size = '50,23'
    $quitTxtBox.DialogResult = [System.Windows.Forms.DialogResult]::No     # 'I`m Up' = No

    $basicForm = New-Object System.Windows.Forms.Form
    $basicForm.StartPosition = 'CenterScreen'
    $basicForm.Size = '250,100'
    $basicForm.Controls.Add($snoozeTxtBox)
    $basicForm.Controls.Add($quitTxtBox)
    $basicForm.TopMost = $true

while ($Snoozevar -eq 'Yes'){

    Start-Process "D:\Programs\Winamp\winamp.exe" /PLAY                    # Start Winamp /autoplay

    Start-Process D:\Programs\nircmd\nircmd.exe -ArgumentList " setsysvolume 65535" #Max Volume

    $Snoozevar = $basicForm.ShowDialog()                                   # Call Menu, assign output to $Snoozevar

    $pro = Get-Process -Name "winamp"                                      # Kill winamp post menu selection
    Stop-Process -Id $pro.Id
    $pro = ""
    
    if ($Snoozevar -eq 'No'){                                              # Clean up powershell
        $pro = Get-Process -Name powershell
        Stop-Process $pro
    } #end if

    $rngvar = Get-Random -Minimum 540 -Maximum 720                         # Time to Snooze (9-12 minutes)
    Start-Sleep -Seconds $rngvar

} #end while
# SIG # Begin signature block
...
# SIG # End signature block

This is my first time asking a question here, please forgive and point out mistakes in forum standards.

Thank You in advance!

By *Task Manager*, I presume you meant to say *Task Scheduler*? Task Manager doesn't run scheduled tasks. — Ken White, Jul 14 '20 at 03:05
Is "Run whether user is logged on or not checked" ? If not, task won't run if you are not logged in. If yes, task won't run interactlively. Is it running on a PC or laptop ? Default condition is to only run if the computer is on AC power. — Sage Pourpre, Jul 14 '20 at 03:17
Try to add `Start-Transcript -Path "Some\Path\AlarmLog_$(get-date -f 'yyyyMMdd').txt"` / `Stop-Transcript ` at the top and bottom of your script to record what is happening... You might be able to see what's failing or gain more insights from there. — Sage Pourpre, Jul 14 '20 at 03:21
In `Task Scheduler`, what does the `Last Run Result` column show for that task after a failure? If you right-click the task and select `Run` does it always succeed? — Lance U. Matthews, Jul 14 '20 at 03:37
@SagePourpre Thank you for showing me Start/Stop Transcript. I discovered my winamp is crashing thanks to it failing ```$pro = Get-Process -Name "winamp"```. All manual runs have failed tonight, leaving me with ```Last Run Result: 0xFFFFFFFF```. I have modified the task settings to give it the best chance to run and I'm taking a look at winamp now. — SHachey, Jul 14 '20 at 04:34

Sage Pourpre · Answer 1 · 2020-07-14T05:35:42.413

Here's a summary of the things that can be done to diagnose an inconsistend scheduled task execution.

Since your task is interactive (have a form), Run whether user is logged on or not should be left unchecked. While you'd normally want it checked most of the time, tasks that interact with the user (popup / forms / etc...) won't work properly if thus option is checked.
Add Start-Transcript -Path "Some\Path\AlarmLog_$(get-date -f 'yyyyMMdd').txt at the beginning of your file and Stop-Transcript at the end to gain more insight on when it fail
Make sure to check the Conditions tab as there are additional constraint that could affect task execution (eg: By default, task will not execute if on battery power)
If the task is running under a different user or in a different context (eg: with Highest priviledges), try to execute your script in that context to see if it fail (for instance, start Vscode / ISE using that context and run the task)

If you have multiple set of operations, you can wrap them in Try / Catch block so if one set fail, you can perform additional logging and also decide whether or not the task should be cancelled altogether or continue through. (Note: When using try/catch, you'll want to set -ErrorAction Stop on the functions that have that parameter to make sure they get caught properly in the catch block.

References

Msdocs - Start-Transcript

Msdocs - Task scheduler -Security context for running task

PowerShell script lacks consistency when run through task scheduler, am I missing something or is this Windows being Windows?

1 Answers1