Prevent Spotify from starting when Windows boots by disabling automatic startup.
1. Open Spotify.
2. Select Edit > Preferences.
3. Scroll all the way to the bottom to the Open Spotify automatically after you log into the computer section, then select the Don’t open automatically option.
The setting is automatically saved once it’s selected. Now Spotify should no longer automatically launch whenever you start your computer. I should mention that I discovered a service called SpotifyWebHelper that allows you to start Spotify from a web page. You can disable SpotifyWebHelper from starting by unchecking the Allow Spotify to be started from the Web option.