The Startup Sprawl
When you log into your Ubuntu desktop environment, you expect a clean, empty workspace. However, certain applications (like messaging clients, cloud synchronization tools, or background monitors) configure themselves to automatically launch the moment your user session begins. If you install several of these tools, your boot process slows down significantly as the system struggles to load them all simultaneously. Furthermore, you might find yourself immediately bombarded with several open windows that you have to manually close before you can actually start your intended work.
Managing the Startup Applications Utility
To speed up your boot time and stop Ubuntu from automatically launching specific applications when you log in, you must remove them from the system’s startup registry.
Press the Super (Windows) key to open the GNOME Activities overview. Type Startup Applications into the search bar and press Enter to launch the utility. A small window will appear titled “Startup Applications Preferences,” listing all the programs configured to run automatically at login. Scroll through this list to find the offending application (e.g., Skype, Discord, Nextcloud). To stop it from launching, simply click the checkbox next to its name to uncheck it. The change is saved immediately. If you want to permanently delete the autostart entry from the list rather than just disabling it, select the application name so it is highlighted in orange and click the Remove button on the right side of the window. The next time you restart your computer or log in, that application will remain closed until you open it manually.