How to check if ini file exists with Wix Toolset

Question

I have an .ini file with configuration. I need to check if it exists in new installation to avoid creating it again. Besides if the new .ini have new fields add to the exist

Answer 1

Set NeverOverwrite="yes" on the .ini file's component and then handle the update via a custom action.

Edit: Generally it is much better to use the IniFile table as explained in my answer since you get rollback and merge capabilities. However, some people prefer the INI file installed as a file to allow easy modification of the file from outside the MSI file. Though not preferred, this does allow people to "hotfix" the INI file directly on the installation media location. Teams can use this to have the installer pick up the latest INI from development. There are technical problems with this that can be handled via a custom action (most significantly file replacement issues on install). It is also possible that an INI file can feature non-standard elements and formatting that doesn't fit in the IniFile table (rare, but possible - people with sense then use a different file extension than ini). As already explained, I would strongly advice against updating INI files via your own custom action, unless you are doing something very special - that's actually needed. It is complicated to implement and to get right.