The first method: Click "Start", select "All Programs" and find DVDFab on the list, or just search for DVDFab 12, and then pick the "Uninstall" option.
The second one: Go to the default path C:\\Program Files\\DVDFab\\DVDFab 12 or to where you have installed DVDFab, find the uninstall.exe, and then double-click on it to complete the uninstallation.
And the third one: You can uninstall DVDFab from "Control Panel"-->"Add/Remove Software" safely.
Note: If you want a complete uninstallation, be sure to check the option "Remove the configuration".