Quicktime player

how to delete goPro videos from quicktime player

If you mean you want GoPro player windows to close when you quit the QT7 (or QTX if in native compatible format) media player and your global System Preference is not set to automatically "Close windows when quitting an app," then hold down the 'Option' key when quitting the QT7/QTX app as seen below:

If you want all apps on your system to automatically close any currently open document windows when quitting their associated app, then set the "Close windows when quitting an app" option under the 'General' tab of the System Preferences window. (In this case, holding down the 'Option' key will tell the main app to remember and reopen the document automatically the next time the app is opened.)

If you are referring to the 'Open Recents' menu, clear the menu and/or reset the 'General' tab of the System Preferences window "Recent items:" pop-up option to 'None' as desired: