This brief guide will show you how to stop Spotify from opening up automatically when your PC (or Mac) starts up.
With Spotify open, select Edit from the top menu and then Preferences… from the drop-down list. Note: Mac users select Spotify from the Apple Menu and then Preferences from the drop-down list.
Scroll down the Preferences section and find the button titled SHOW ADVANCED SETTINGS. Click it.
Locate the Startup and Window Behaviour section and click the menu next to Open Spotify automatically after you log into the computer
Select No from that menu. That’s it! Spotify will no longer start when your computer does.