You may not want Dell Display Manager to start automatically when you logon. When you setup the program there is an option to run it as administrator, in which case it won’t run automatically. However, certain security policy configurations may permit a startup program to run with administrator privileges.

Even if you remove manually Dell Display Manager from all possible startup locations in the registry and the Start menu, you may still see that the program runs automatically when you logon!

To finally make sure Dell Display Manager behaves, remove its shortcut even from its normal (not startup) Start menu folder. If you do this, the program won’t run again at logon, but you will also not be able to type its name in the Start menu and run it.

You have to create a desktop shortcut, or add it to a launcher, or configure a scheduled task in order to run it easily.