Hey !
@Mazin:
Thanks, I tried your switches. Issscript.msi seemed to work with the /qn switch but Anti-Hacker.msi with the /QN switch resulted in an error message (see attached picture).
Using the /QR switch as you suggested did not work either ( got an error message saying that this installation could not be installed through the msi package and one should use the setup.exe --- it was in German so I am not attaching a picture.
@Bashrat
Thanks, I will probably do that if there is no other choice but I would prefer an application switch. Looks nicer and does not allow the user to somehow use the mouse or keyboard thereby accidentally causing the script to break.
If there are more ideas, please keep them coming !