InstallAware

Does IA have support for replacing locked files, because here is my dilema; my IA installer installs a Package Deployment service on machines on my network, then when I release a new build of this package it forces an uninstall beforehand obviously stopping the service which I do not want it to do. I have found a tool called inuse and a registry key called PendingFileRenameOperations, and I wondered how I would go about:
1) Not forcing previous version uninstall
2) Detecting the upgrade and copying files with a *.new extension and adding a line to PendingFileRenameOperations.

Nothing is hard coded, if you look in your script, you'll see the portion that uninstalls the old version and can comment it out...

However, Windows Installer technology itself will not allow you to to just add files to an existing installation, unless you do them via API directly bypassing MSI, or build an MSP patch instead.