Get-Child Item not working through task scheduler - powershell

Question

I am trying to run this script through GPO deployed scheduled task:
$registryPath = 'HKLM:\Software\CC\PST_Discovery_Script\Already_Run'
if (!(Test-Path -Path $registryPath)) {
$dir = "c:\Users"
$ext = "pst"
Get-ChildItem "$dir" *$ext -r | Select-Object FullName,LastAccessTime,LastWriteTime,CreationTime,#{N='Owner';E={$_.GetAccessControl().Owner}}, #{Name="MegaBytes"; Expression={"{0:F2}" -f ($_.Length / 1MB)}}, #{N='Hostname';E={$env:computername}} | export-csv "c:\PST_Discovery.csv" -Append -NoTypeInformation
New-Item -Path HKLM:\Software\CC\PST_Discovery_Script -Name Already_Run –Force
}
It works fine if I run the script manually through the Powershell console/ISE, but not through a scheduled task.
If I run it through a scheduled task, I know the script is running because it reads the registry key, and if it doesn't exist it writes a registry key, but it does't actually run the get-childitem line or export a CSV.
The scheduled task shows up on the client, and it's running using a Domain Admin credentials (me)
EDIT: Sorry, my formatting for the code went all wrong, i think it should be fixed up now
kaspermoerch: Yes, it's a domain admin, and thus has full permissions over the file system
boxdog: I actually had it writing to a UNC share, but changed it to local computer because it wasn't working. I'll try some other combinations of output location and user.
TheIncorrigible: Originally it was system, but it wasn't working so I edited the pushed out scheduled task and am using my domain admin account.
Adam:
- Yes, scheduled task is created
- Yes, task runs script using following code: Powershell.exe -ExecutionPolicy Bypass \server1\share1\PST_Discovery_Script.ps1
- Yes, it runs using my DA creds
- Yes, the file isn't created, though it still writes the registry value
I've checked scheduled task, see my screenshot. I'm elevating the task scheduler and manually running the task.

Answer 1

Just to make sure I understand correctly.
The scheduled task is created.
The scheduled task runs a script containing the following code.
The scheduled task executes the script using your credentials.
Your account is in the Domain Admin group.
By "not working", the PST_Discovery.csv file isn't created.
Correct me if I misunderstood anything.
First: I'd verify the scheduled task is running in an elevated context (runas administrator). Even if the account executing the task is an administrator, the job needs to run in an elevated context.
Second: I'm curious how this works for you but not me. I've never seen a call to Select-Object quite like you've got. If I try to pipe an gci | Select-Object -Property #(...what you have...) | Export-Csv... I get an exception complaining about the FullName.
$registryPath = 'HKLM:\Software\CC\PST_Discovery_Script\Already_Run'
if (!(Test-Path -Path $registryPath)) {
$dir = 'c:\Users'
$ext = 'pst'
Get-ChildItem -Path $dir -Filter *$ext -Recurse |
Select-Object -Property #(
FullName
LastAccessTime
LastWriteTime
CreationTime
#{N = 'Owner'; E = {$_.GetAccessControl().Owner}}
#{Name = "MegaBytes"; Expression = {"{0:F2}" -f ($_.Length / 1MB)}}
#{N = 'Hostname'; E = {$env:computername}}
) |
Export-Csv -Path c:\PST_Discovery.csv -Append -NoTypeInformation
New-Item -Path HKLM:\Software\CC\PST_Discovery_Script -Name Already_Run –Force
}
You're 100% sure that works? I had to change that snippet to the following:
Select-Object -Property #(
, 'FullName'
, 'LastAccessTime'
, 'LastWriteTime'
, 'CreationTime'
#{N = 'Owner'; E = {$_.GetAccessControl().Owner}}
#{Name = "MegaBytes"; Expression = {"{0:F2}" -f ($_.Length / 1MB)}}
#{N = 'Hostname'; E = {$env:computername}}
I'm running Powershell 5 on Windows 10. I'm executing your example from the CLI.

Answer 2

I copied the code format you laid out, and it worked fine for me.
A quick and easy method to capture anything going wrong would be to change the error action preference to stop at the start of your script so that the process exits at the first error and any errors will flow back to the scheduled task's Last Run Result. From there you should be able to see the exception.
$ErrorActionPreference = 'Stop'
That should at least provide a starting point if you haven't already solved it. If that returns anything other than 0, then you know to build in some error handling with try/catch and perhaps an output log, to help you get to the bottom of it.