Most Tablet PCs have a small Windows Security button next to their view screen. Pressing the button during the start-up process displays the Windows log-on screen, and opens the Task Manager when Windows is already running.
Windows does not allow you to use the Ctrl-Alt-Delete keys displayed on a Tablet PC's touch-screen keyboard to perform the tasks that are normally activated by pressing these keys. The Windows Security button is used to perform these tasks instead.
You can configure Windows so that it does not ask you to press the Windows Security button at log-on. You cannot make any of the other tablet buttons on your tablet PC perform the Ctrl-Alt-Delete key tasks that the Windows Security button performs.
If you connect a physical keyboard to your Tablet PC, you can use the Ctrl-Alt-Delete keys on it and do not need to use the Windows Security button at all.
The Windows Security button is part of the physical design of a Tablet PC and is programmed by the computer's manufacturer. Not all manufacturers designate one of their tablet buttons as a Windows Security button.