You definitely have something going on with your machine if closing the app doesn't revert any lag your experiencing. LaunchBox doesn't leave anything open or running once the save event is done (which should only last a few seconds after closing the app) and so there would be nothing to affect your PC. When LaunchBox is open you can launch Task Manager and see if your machine is bottlenecking at all. You can also then close LaunchBox and make sure the process closes out (again it won't be removed from the list until the save event finishes, this shouldn't take longer than 60s, if it lasts longer let us know).