JSI Tip 4078. You can NOT log on to Windows NT 4.0 SP6a once the LOGON.SCR screensaver starts?

If you experience the subject error and have to restart before being allowed to log on, use Regedt32 to navigate to HKEY_USERS\.DEFAULT\Control Panel\Desktop. Double-click the SCRNSAVE.EXE value name, a REG_SZ data type, and set the data value to the full path to the LOGON.SCR file. The full path is normally C:\Winnt\System32\Logon.scr.