Winlogon handles interface functions that are independent of authentication policy. It creates the desktops for the window station, implements time-out operations, and provides a set of support functions for the GINA.

For information about See
Creating desktops and registering a secure attention sequence (SAS)
Initializing Winlogon
The different states in which Winlogon can run
Winlogon States
Time out operations
Supported Dialog Box Service Time-out Operations
Sending messages to the GINA while a dialog box is displayed
Sending Messages to the GINA
Support functions for the GINA
Winlogon Support Functions