When I posted that, some of your code was not available so the $systemdrive var was coming up empty. With your newly posted code, $prffile would now be:
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
which is still an invalid filespec!

Let me paint you a picture.

$systemdrive = 'C:'
$scriptdir = 'C:\Scripts'
$prf = '\\DC\Netlogon\sr-kixscripts\outlook.prf'

So then, if you concatenate:
$scriptdir+'\'+$prf = 'C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf'
you have an invalid filespec. I really don't understand why you are concatenating those two vars in the first place because together they do not make up a proper path! There is no way that it can work anywhere else in your script.

Maybe if you see it a few more times it might sink in
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf
C:\Scripts\\\DC\Netlogon\sr-kixscripts\outlook.prf

Get the picture?
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