The application I'm working on provides self-upgrade functionality, which replaces the current application when a new version is released (via ftp process).

I don't have problem replacing the existing application (.exe file). However, sometimes addinging or updating .dll and .ocx files with the new version is required, and thus might need to know where the file is installed (because it's not under the program directory) and do something to the window's registry.

In the past, when adding or updating these files is required, a new set of setup disks is distributed, uninstall old version followed by installing a new version and let setup wizard do the job. This is an inefficient and tedious process.

I'm looking for a way similar which automatically replaces the required files in the required directory -- similar to installing service packs. How to find out where the originally file is and update the registry with the new version?

Any suggestions on how can this be done, preferably without using 3rd party software?