What do you mean, how do you want to “get back to start”? How does it “embed files”?
It’s common for applications to leave configuration untouched when uninstalling, although many applications ask whether to remove everything. Kicad just leaves the configuration files as they were, so uninstalling and reinstalling doesn’t help if you have problems. See Where are the configuration files (settings, library tables)? if you want to reset the configuration and the library setup.