Continuous Grow file Setupapi.log, WINLOGON High CPU usage and takes a long time to log on to a Windows.

Use filemonitor or ProcessExplorer to diagnostic. C:\WINDOWS\setupapi.log contains information about application installation, it log file is used to trace the cause of problems should they arise after an installation of a device or drivers.

Incident:
In my case file C:\WINDOWS\setupapi.log is big and WINLOGON. EXE consume high CPU went users login in the server.

Workaround:

• Open your registry editor.
• Go to “HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Curr entVersion\Setup\LogLevel” registry key.
• Set LogLevel key to 0
• Restart server.

More Info:
http://msdn.microsoft.com/en-us/library/ff550845(v=vs.85).aspx
http://support.microsoft.com/kb/958909/es