When I copy an app I downloaded onto my thumb drive, I move everything into the dowloads folder on the dock, then I click on the item, sometimes its a zip file, others it is a hard drive icon, & it opens up. I then go to the apps folder, & move all items from the download back to the downloads in the dock, & just have the actual app in the apps folder. I notice when I open vlc player, the hard drive icon that came with it as a download gets placed on the desktop. When I shut down vlc player, I have to eject the hard drive icon off the desktop.