Not quite sure what you want here (what is suppr?), but to send a Ctrl-Alt-Del signal to remote server, right-click the VNC viewer app in your taskbar and one of the options is send ctrl-alt-del.

In this guide, we show you how to perform Ctrl+Alt+Del on a Remote computer using Remote Desktop Connection. Have you ever wondered why the most used key combination in the Windows environment doesn’t ...

I am using TightVNC's client viewer and RealVNC's client viewer.<BR><BR>I understand that you can send the ctrl alt del command via a mouseclick through the right clicking of the title bar. There's an ...