First click an entry on the list. The Block, Unblock and Delete commands are on the toolbar and in the right-click menu. Buttons that cannot be used for the selected entry are greyed out.
Which commands are available
• nothing selected – none;
• a Registry or Folder entry, not blocked – Block and Delete;
• a Registry or Folder entry, blocked (grey italics) – Unblock and Delete;
• an App entry, not blocked – only Block;
• an App entry, blocked – only Unblock.
Blocking and unblocking
Block turns a program off in startup without removing it: the entry stays on the list (grey italics) and Windows stops starting it. Unblock restores the entry exactly as it was.
Registry - Run and Folder entries are marked as disabled the same way as Task Manager does it – the command in the registry and the shortcut in the folder stay unchanged, and the state is shared with the switch in Task Manager. Windows has no such switch for the other Registry entries (Run once, Services) – for them the program adds a character to the file name in the command, and Unblock removes it.
App - Startup task entries are turned off and on with the same switch as in Task Manager and in Windows Settings (Apps > Startup) – the state is shared by all three places.
Before blocking and unblocking, the program asks for confirmation – the question shows the command of the selected entry. No leaves the entry unchanged.

Before blocking, the program asks for confirmation and shows the command of the selected entry.
A block takes effect at the next sign-in – it does not close a program that is already running.
Deleting
Delete asks for confirmation first – the question shows the command of the selected entry. After Yes the entry is removed and deleting cannot be undone.

The question before deleting. After Yes the entry is removed and this cannot be undone.
If you may want the program back later, block it instead, or write down the path from the Name column and add it again later with the Add button.
Deleting is useful for cleaning up leftovers of uninstalled programs: a registry entry without a command is shown on the list as a name in square brackets, for example [GalaxyClient] – Windows runs nothing from it.
Why an app cannot be deleted
App - Startup task entries cannot be deleted – the startup task is part of the app and disappears only together with it. To stop the app from starting with Windows, block it. That is why the Delete button is greyed out for such an entry.
Changes made in Task Manager
An entry disabled in Task Manager is disabled in Startup Tool For Windows as well, and vice versa. If you change the state in Task Manager while the program is open, click Refresh so that the list shows the current state. Task Manager does not show the other Registry entries (Run once, Services).
Other help topics
More parts of the Startup Tool For Windows help on our blog: the startup program list; adding a program to startup; administrator rights, language, theme and troubleshooting.