Powershell Scripting -- Docx to PDF - powershell

Question

I have a script (below) that converts docx to PDF. However, after it gets to file 204 or 205, I get a memory exceeded message and the process stops. I have about 40,000 docx that need to be converted. Can someone help with making this more efficient or possibly add a loop that closes the application after every 150 documents then re-opens the application and continues? Any help would be appreciated.
$documents_path = 'C:\Users\jgentile\Desktop\Purdue\DocX\All'
$word_app = New-Object -ComObject Word.Application
$i=0
Get-ChildItem -Path $documents_path -Filter *.doc? | ForEach-Object {
If( $i%150 ) { $word_app.Quit(); $word_app = New-Object -ComObject Word.Application }
$document = $word_app.Documents.Open($_.FullName)
$pdf_filename = "C:\Users\jgentile\Desktop\Purdue\PDFs\$($_.BaseName)_Discipline.pdf"
$document.SaveAs([ref] $pdf_filename, [ref] 17)
$document.Close()
$i++
}
$word_app.Quit()

Answer 1

The way your if statement is set up, it would execute every iteration of the loop except for 150, which I'm guessing is not what you intended. Also, you should release the comobject in order to avoid out of memory exception
If(!($i%150)) {
$word_app.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($word_app)
Remove-Variable word_app
$word_app = New-Object -ComObject Word.Application
}
http://technet.microsoft.com/en-us/library/ff730962.aspx

Answer 2

An if-test needs a true or false value. 1%150 will return 1, 2%150 will return 2 etc. -> value is not null. You're if-test will always be true, except for 0 which is converted to false. So your script actually works the opposite way of how you want it.
You should test if $i%150 -eq 0. That will only happend when $i is 0, 150, 300, 450 etc. If you don't want it to run on 0, start your $i on 1. :)
Try
If($i%150 -eq 0) { $word_app.Quit(); $word_app = New-Object -ComObject Word.Application }
You could also just flip the if-test(turning false to true) using if(-not($i%150)), but I think -eq 0 is more readable.
UPDATE: As #Cole9350 pointed out, you should also release the Comobject after calling Quit() to free up the handle on the resource(process) so that Word closes properly. Like:
If($i%150 -eq 0) {
$word_app.Quit()
[System.Runtime.Interopservices.Marshal]::ReleaseComObject($word_app)
$word_app = New-Object -ComObject Word.Application
}