Software Deployment

This link contained information that was close to what I had thought to do
http://itninja.com/link/how-do-you-install-the-notes-client-without-user-intervention?8

The current script I have copies the actual (final 'latest' version of wdefender) "windowsdefender.msi" installer to "c:\program files\windows defender" then runs the installation quiet. Copying over the windowsdefender.msi installer and then running it on the client machine does two things:

1)uninstalls all previous versions automatically (beta)
2)installs latest version

I am finding however that after doing the suggested MSI edits through ORCA msi editor, on some machines the installation does not 'update' correctly. I get some kind of error message that tells cannot find network blah blah windowsdefender[1].msi. It's as if the machine thinks there is already another windowsdefender.msi package in there or I get "The software you are using is counterfeit" error message (most likely from deleting a row in the msi editor) Again, this is not on all machines.

This is what the script looks like right now.
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if exist "c:\wdefender.txt" goto end
if not exist "c:\program files\windows defender" goto end
if exist "c:\program files\windows defender" goto update
:update
copy \\Server\share\windowsdefender.msi "c:\program files\windows defender"
cd\program files\windows defender
windowsdefender.msi /quiet
echo %date% > c:\wdefender.txt
:end
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I would like some input or suggestions if you've come across this yet or how you've deployed windows defender

Thanks