SplashTextOn not staying on when run as shutdown script

[MarkBe]

I run a compiled .exe as a group policy shutdown script to update various software. The function below is called to run both .exe and .msi installers (hence the two sections). When I run this in a user session the SplashTextOn window stays visible in the background throughout the entire install but when this is executed as a shutdown script the SplashTextOn window disappears before the installer has finished (during the RunWait)

Func _InstallSW()
    SplashTextOn("Installing", $InstallingUpdateMessage, 500, 400, -1, -1, $DLG_NOTONTOP)
    FileCopy ($SourcePath & $SWInstaller, $WorkingDirectory & $SWInstaller, $FC_OVERWRITE + $FC_CREATEPATH)
    If StringLower(StringRight($SWInstaller, 4))=".exe" Then
        RunWait ('"' & $WorkingDirectory & $SWInstaller & '"' & $InstallerSwitches)
    Else
        RunWait ('msiexec /i "' & $WorkingDirectory & $SWInstaller & '"' & $InstallerSwitches)
    EndIf
    SplashOff()
EndFunc ;==>InstallSW

Is there a better function to use or something I can add (e.g. While)? I need it to remain behind the installer's progress windows so it shows when the installer is running a background process (to prevent the user from forcing the power off thinking it has hung)

[JLogan3o13]

Since you mention it is a shutdown script, are you running it in the SYSTEM context, or still as the logged in user? Also, are you seeing it at all (brief flash then disappear) or no splash text at all?

[MarkBe]

On 14/04/2017 at 0:07 AM, JLogan3o13 said:

Since you mention it is a shutdown script, are you running it in the SYSTEM context, or still as the logged in user? Also, are you seeing it at all (brief flash then disappear) or no splash text at all?

Yes, SYSTEM context. The splash text shows for some time. During file copy (third line of script), and during the first part of the installer (during the RunWait) but then goes away about 2 minutes in.

p.s. shutdown scripts are set to 'run visible'