IA12, Native Engine.
My installer is trying to install files in a directory under C:\Program Files.
I have these split into two groups, 'always overwrite' and 'never overwrite'.
I am finding that the 'always overwrite' group will be installed if not yet present, but are not installed if a file of the same name (different content) was already present.
The actual lines in the installer are like this:
Comment: Install 'never overwrite' files.
Set Variable NATIVE_OVERWRITE to NEVER
Install Files ... (the 'Never Overwrite' checkbox is checked)
I think this is working OK.
Comment: Install 'always overwrite' files.
Set Variable NATIVE_OVERWRITE to ALWAYS
Install Files ... (the 'Never Overwrite' checkbox is unchecked)
It is these files which are not overwriting existing ones.
If I uninstall, they are not removed (as the installer had not installed them).
I don't know whether the checkbox on the dialog is intended to be scoped out by the variable, hence the 'belt an braces' settings.
I have tried setting the Project Settings→Project →Summary →UAC Elevation setting to either Elevate Administrators Only or Always Elevate, and have seen no difference with the above behaviour. I believe that the elevation is actually happening (in case you think a security policy is inhibiting it). At least, the elevation permission dialog is displayed.
Do you have any ideas please, or do you need further information?