FWIW: I used IS 3.5 for our last release and it was nothing but a headache. Many times it would not complete an install, displays rediculous error messages to the end user, sometimes tries to run the installer every time the user boots!. I am not sure that the problems reside within IS or the MS windows installer services - a question of no consequence to me. I need an installer that is a slam dunk for every one of my end users - unfinished installs are ot acceptable. I went back to the WISE INSATLL SYSTEM PROFESSIONAL script based installer. IT is easier to configure and the resulting setup.exe executes unattended, perfectly every time. That is my description of a good installer.