I found contradictory information:
1) winlogon.exe is a process which is registered as a trojan. This Trojan allows attackers to access your computer from remote locations, stealing passwords, Internet banking and personal data. This process is a security risk and should be removed from your system
2) winlogon.exe should not be disabled, required for essential applications to work properly. It is highly recommended that you run a FREE performance scan to automatically optimize memory, CPU and Internet settings.
So, what is the truth ?