logonui - logonui.exe
logonui.exe (logonui stands for Windows LogOn User Interface) is a Windows NT/2000/XP generic process used for managing the Log-On and Log-Off screens, allowing the computer to switch easily from one user to the next.
The process logonui.exe is not in any way a virus, a worm, a Trojan horse, spyware, or adware.
The file that corresponds to this process is normally found in the directory "%SystemRoot%\system32\logonui.exe" (where %systemroot% is usually C:\WINDOWS by default).
It is a critical system process which may not be terminated.