Windows NT does not send alert messages on a real-time basis.
Alert messages are sent every 5 minutes, unless 10 alerts are pending or 5% of all network operations generate an error.
To alter this behavior, use Regedt32 to navigate to:
Edit or Add Value name AlertSched, as a type REG_DWORD. In the DWORD Editor, enter the number of minutes, using the Decimal Radix. The default is 5 minutes and the range is 1-65535 minutes.
Additionally, you can Add Value name ErrorThreshold as a type REG_DWORD. Enter the number of errors that must occur to trigger an alert before AlertSched elapses, using the Decimal Radix. The default is 10 and the range is 1-65535 errors.
You may also Add Value name NetworkErrorThreshold as a type REG_DWORD and enter the % of failed network operations that will trigger an alert before AlertSched elapses. The default is 5% and the range is 1-100%. Use the Decimal Radix.
You must restart your computer for these changes to take effect.