There is no apache and php error message but it could not proceeded at login.php.
At windows event logs, I found mysql message.
Message: The description for Event ID '-1073741724' in Source 'MySQL' cannot be found. The local computer may not have the necessary registry information or message DLL files to display the message, or you may not have permission to access them. The following information is part of the event:'Event Scheduler: Loaded 0 events
Event ID / Instance ID100 / 3221225572
Date & Time: 1/13/2012 10:47 AM
Time Written: 1/13/2012 10:47 AM
Entry Type: Information
Does this message show my login problem ?