Unable to print PDFs or office documents via Scheduled task - powershell

Question

I have a scheduled task set to run on a machine overnight. This task will iterate through a folder printing all the files found therein. I can run the process without issue while logged in however it does not print when run via the scheduled task.
More Info:
The scheduled task executes a powershell script that performs multiple functions such as generating and emailing reports, copying files across network folders and finally printing the contents of a folder. All of these tasks are performed without error if the executing account is currently logged in. If the account is not logged in and run via a scheduled task everything except the printing of Office and PDF documents works correctly (Text documents print fine).
Here is the function I am using to print the documents.
Function Print-File($file)
{
begin
{
function internal-printfile($thefile)
{
if ($thefile -is [string])
{
$filename = $thefile
}
else
{
if ($thefile.FullName -is [string] )
{
$filename = $thefile.FullName
}
}
$start = new-object System.Diagnostics.ProcessStartInfo $filename
$start.Verb = "print"
[System.Diagnostics.Process]::Start($start)
}
if ($file -ne $null)
{
$filespecified = $true;
internal-printfile $file
}
}
process
{
if (!$filespecified)
{
$test = write-Host process ; internal-printfile $_
}
}
}
When running from a scheduled task I can see the process start (Winword or AcroRd32) as I am dumping output to a text file however I do not see anything print. One other difference I noticed is that when I use this function while logged in the Applications other than Adobe reader (Office Apps) start to print the document then close. However when run from a scheduled task the applications do not close on their own.
I would appreciate any feedback, suggestions or pointers at this time as I have hit a wall as far as knowing what else I can check. I would also take suggestions as to an alternative way to accomplish the printing of the files. (NOTE: I cannot predict the file type in the folder)
NOTE: These symptoms are present on two machines, Windows server 2008 and Windows 7, both running Office 2007 and Adobe Reader 10.1.7

Answer 1

I'm trying to do the same thing that you are attempting. I'm pretty sure what you're running into is session 0 isolation. You can read more about it at this MSDN site and this Windows blog post.
I haven't tried the suggestions in the following answer to another question on SO, but it might be worth a try.
Creating Desktop-Folders for session 0
Here is another guy who is trying to print without having a user logged into the machine. There is an answer from someone who claims to know how to do what we're all trying to do, but he doesn't actually post the answer.

Answer 2

Too late for OP, but for future readers... I had the same problem, but with a windows shell .bat file, not PowerShell. As a scheduled task, the script would launch AcroRd32.exe /t, but it wouldn't print anything. Then after a delay, Acrobat was stopped, and the file was moved to the "Printed" folder like everything was good. It printed fine standalone, just not as a scheduled task.
(Background: I'm running Windows 10 x86 on one older computer so that we can use our two bulletproof HP LaserJet 1000 printers. However, the program we used for this in Win 7, batchdocprint, is incompatible with Win 10 and the company is gone. Due to having to learn arcane syntax and workarounds, I've spent way more money in hours getting a few lines of code (below) working right than the program cost, but I couldn't find a suitable replacement. The programs that I found either printed incorrectly, or had options for only one printer.)
The problem for me did seem to be Session 0 isolation blocking GDI+. I went with the seemingly "spammy" suggestion of getting Foxit Reader. It worked, and like Acrobat, the reader is free. I just replaced the path to AcroRd32.exe with the path to FoxitReader.exe
I don't think this will ever be possible with Acrobat Reader. The CLI is not officially supported, so the likelihood of Adobe ever changing it to print without launching the GUI is minimal.
As far as other file types, it depends on what you're using to print them, and whether it can open and print without a GUI. I haven't decided whether to implement this for other common file types so that we can just drag-and-drop, or to keep forcing the users to use the Acrobat PDF printers that are set up to save PDFs in the hot folders. Right now, it's the latter.
My code, for reference, to hopefully save someone else my headache. I only changed/shortened names, and removed duplicate code for the second folder/printer. Note that taskkill requires administrative privileges. Also, you probably need to have a folder named "Printed" in your hot folder, since I don't check for its existence:
#ECHO OFF
REM Monitors folders for PDF's and prints.
REM Use PING for delay - no built-in sleep functionality.
REM Using START backgrounds the process so the script can move on.
:LOOP
cd C:\Hot Folder\
for %%a in ("*.pdf") do (
start "" "C:\Path\To\FoxitReader.exe" /t "C:\Hot Folder\%%a" "HP 1000"
ping 1.1.1.1 -n 2 -w 5000 >NUL
taskkill /IM FoxitReader.exe /F
move /Y "%%a" ".\Printed\%%a")
ping 1.1.1.1 -n 2 -w 5000 >NUL
goto LOOP

Answer 3

Not sure if you ever found the solution to this, but it happens that the printer to be used by task scheduler job should be registered under:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Printers (local printers)
vs
HKEY_Current_User\Printers\Connections (session printers)