Have you tried logging the installation process and seeing if there's any clues in there? Or checking the Event Log on the system to see if there are any clues?
I can't give you a direct answer to your question. In some of my past (mistakes) installers, I've run into problems with some DLLs I was trying to replace being held open by some other processes that I wasn't expecting. Java was bad, in my case.
I've got a batch file called testinstaller.bat that looks like this:
[PHP]rem Set name set SETUPFILE=C:\Temp\%1 @echo Installing software (this may take a few minutes)... pushd C:\temp start /wait %SETUPFILE% /debuglog"c:\temp\install_%1.log" /w /v"/L*v c:\temp\upgrade_%1.log" popd[/PHP]
Have to put the file in C:\Temp in my case, and I force all my log files there. Hopefully that gives you some idea. There are two separate logs because one is that InstallShield internal logic, and the other is the record of what my authored install does.
