\AppData\Roaming\Embarcadero\BDS\ \EnvOptions.proj That's where Delphi|C++ Builder keeps its system-wide includes, lib. dirs, browse dirs, etc. If you frequently use 3rd party components upgrade|rebuild|reinstall steps, as I do, saving this file before components re-install, is a must. Component installers may mangle its contents, breaking file lookup settings, or whatever. So, just save the copy of this file somewhere, then, after component(s) are re-installed, compare the new one with the old one, better using some diff tool, and restore broken|deleted paths, if needed. Well, it appeared, thet this file is created from paths data, IDE stores in registry, so, upon each re-start, IDE re-creates that file from scratch. This proj file is used by msbuild tool, when command line compilation required. Seems that I have to write IDE settings importer-exporter after all.