JiMooh

Hi I've done a import of a Mame rom fullset (0.249). Of course I've done some selection "no casino, no fruits..." Once I've edited what was left, 1500 games approximatly. I want to clean up my rom folder... and I don't understand. I've deleted the game in launchbox with also delete rom threw launchbox. But I have still a huge folder with I know lots of unused rom files... How can i clean up? I don't want to erase to much files and that "in 3 months" I fianlly realise that the CPS2 (for example) games dont work anymore...