Howtogeek posted a guide about enabling Ctrl+Alt+Del for Task Manager in Linux

In Windows you can easily kill any task by pressing Ctrl+Alt+Del and bringing up the task manager. Linux running the GNOME desktop environment (i.e. Debian, Ubuntu, Linux Mint, etc.) has a similar tool that can be enabled to run exactly the same way.
Setting up global key bindings

The GNOME desktop environment by default uses the Ctrl+Alt+Del shortcut to bring up the shutdown, logout, restart, and hibernate dialog. This is not useful for users who are used to quick access to a task manager.

To change the settings of Ctrl+Alt+Del in GNOME open the keyboard shortcuts preferences. In Ubuntu it is located under System -> Preferences -> Keyboard Shortcuts, and in Linux Mint open the mintMenu -> Control Center -> Keyboard Shortcuts.

  Use Ctrl+Alt+Del for Task Manager in Linux to Kill Tasks Easily