how to enable ctrl+alt+del logon in windows 7

You need to do this work via Registry Editor or Group Policy Editor.

For example, if you want to hide Task Manager or lock some options for some reason, you can use this Ctrl+Alt+Del combination. You can also use Ctrl+Alt+Del to modify the options in Windows Security.You can also do this operation on other applications like VMware Workstation as well as other virtual desktop software. Windows will assume you want to use it on your local computer instead. Some remote desktop applications allow you to send the Ctrl+Alt+Del shortcut to a remote computer via an option in the menu and then expect it to pass through to the application.Besides, you can also use it to restart an Ubuntu Server without having to log beforehand. Ubuntu and Debian are two representatives. You can use Ctrl+Alt+Del to log out on some Linux-based operating systems.You can find more information on this keyboard combination in the following contents. The functions of Ctrl+Alt+Del are not limited to the above contents. This can help you lock your computer, switch to a different user account, log off, use Task Manager, or shut down or reboot your computer. If you have logged on to Windows 10/8/7/Vista, you can use Ctrl+Alt+Del to start Windows Security.

You can refer to this post to enable it: Enable Press Ctrl+Alt+Del Secure Logon On Windows 7 or Vista.

However, this feature is disabled by default. This is called a secure attention protection/sequence. If you are still using these Windows operating systems like Windows XP, Windows Vista, and Windows 7, you can use the Ctrl+Alt+Del command to log in to a Windows user account. That is why you need to reboot your computer properly. Although the page cache is flushed and the volumes are safely unmounted, it is quite possible that the running programs are not closed cleanly and your works/documents are not saved properly.

How to enable ctrl+alt+del logon in windows 7