WinLogon Event Notifications – WLNOTIFY.DLL
Wlnotify.dll is a library that contains application programming interface (API) functions to receive and handle notifications events generated by Winlogon (winlogon.exe) lThese event messages includes lock, unlock, logoff, logon, startup, shutdown, startscreensaver, stopscreensaver, and startshell. It is specific to the current user's session. This is a system file that you'll want to leave in place.
While wlnotify.dll is a perfectly legit file, the WinLogon Notification process can be abused by malicious programs. Third party programs (usually dlls) can tap into this process and use it to run files when your system starts up. It is even possible to start a Win32 application before the user logon.
In Windows Vista and later, Winlogon notification packages are no longer supported. You'll find more information at http://technet2.microsoft.com/WindowsVista/en/library/6ec4ec6d-6b84-44c9-b3af-116589a42b861033.mspx?mfr=true.
Safe
Microsoft