component is solely responsible for calling these APIs in the GINA library. When the Winlogon process starts, it compares its version number to that which is supported by the loaded GINA library. If the GINA library is of a higher version than Winlogon, Windows will not boot. This is done because a GINA library written for a given version of Winlogon will expect a certain set of API calls to be provided by Winlogon. Support for replaceable GINA DLLs was introduced with Windows NT Server 3.51 and Windows NT Workstation 4.0 SP3. Successive versions of Windows have introduced additional functionality into Winlogon, resulting in additional functionality that can be implemented by a replacement GINA. Windows 2000, for example, introduced support for displaying status messages (including verbose messages that can be turned on through Group Policy) about the current state to the user (e.g. "Applying computer settings."), and starting applications in the user's context; this facilitates restarting Windows Explorer automatically if it crashes, as well as starting the Task Manager. Windows XP introduced support for Fast User Switching, Remote Desktop and a more interactive, simplified and user-friendly full-screen logon. End of life In Windows Vista, GINA has been replaced by credential providers, which allow for significantly increased flexibility in supporting multiple credential collection methods. To support the use of multiple GINA models, a complex chaining method used to be required and custom GINAs often did not work with fast user switching. GINA libraries do not work with Windows Vista and later Windows versions. One difference, however, is that GINA could completely replace the Windows logon user interface; Credential Providers cannot. See also List of Microsoft Windows components Winlogon Windows NT startup process References External links Winlogon and GINA, developer information on how the login components interact Customizing GINA Part 1, Developer tutorial for writing a custom GINA. Customizing GINA Part 2, Developer tutorial for writing a custom GINA. pGina, Open Source Windows Authentication Microsoft Windows security technology Windows components