In general, GINAs should monitor SASs on their own however, any GINA that has the standard Ctrl+ Alt+ Del SAS as one of the SASs it recognizes should use the Winlogon support provided for this purpose. Winlogon makes this SAS event information available to GINAs to use as their SAS, or as part of their SAS. Winlogon has special hooks into the User32 server that allow it to monitor Control-Alt-Delete secure attention sequence (SAS) events. In general, this means that the local system will have full access to these objects and that an interactively logged-on user will have read access to the window station object and full access to the application desktop object. Winlogon sets the protection of the window station and corresponding desktops to ensure that each is properly accessible. Winlogon has the following responsibilities: Winlogon also checks if the copy of Windows is a legitimate license starting in Windows XP and later. It creates the desktops for the window station, implements time-out operations, and in versions of Windows prior to Windows Vista, provides a set of support functions for the GINA and takes responsibility for configuring machine and user Group Policy. Winlogon handles interface functions that are independent of authentication policy. In Windows Vista and later operating systems, Winlogon's roles and responsibilities have changed significantly. Increased memory usage for this process might indicate that it has been 'hijacked'. Winlogon is a common target for several threats that could modify its function and memory usage. The actual obtainment and verification of user credentials is left to other components.

In computing, Winlogon (Windows Logon) 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 (requiring another authentication step). Windows 11 lock screen, requiring user to press Ctrl+Alt+Delete.

Clock screensaver windows 7