Wix custom-action dll relies on files installed at execution

Question

I'm using a dll to install a driver that's packaged inside the msi. When I schedule the custom-action for after InstallFinalize it succeeds, but if I schedule it either 1) after InstallFiles 2) after InstallFiles, execute=deferred, 3) after InstallFiles, execute=deferred, impersonate=no, or 4) before InstallFinalize it fails with "file not found" for the .inf file.

I've read This SO post and this page, but still don't understand how I get my driver to be installed.

If I use after InstallFinalize then if for some other reason an error is returned it's too late to abort the installation and it's botched.

Answer 1

According to this answer to the question you linked, you should schedule it after InstallFiles and make it deferred.

Enable verbose logging during your installation, and you'll be able to see when files are copied to the hard drive and when your custom action is called.

After InstallFinalized, your installation is already complete.