Winlogon is the component of Microsoft Windows operating systems that is responsible for handling the secure attention sequence, loading the user profile on logon, and optionally locking the computer when a screensaver is running. Winlogon handles interface functions that are independent of authentication policy. It creates the desktops for the Windows and in older versions takes responsibility for configuring machine and user Group Policy. When Windows starts, Winlogon can execute startup files to automaticlaly run once the shell is started.