This Knowledgebase article describes known Neverfail Heartbeat behavior on Microsoft Windows 2000.
Neverfail Heartbeat V5.0 onwards generates balloon notification messages in Microsoft Windows Server 2003. This Operating System functionality does not exist on earlier versions of Microsoft Windows, for example Windows Server 2000 or earlier versions of Neverfail Heartbeat. Therefore, no balloon notifications will be displayed on screen. Neverfail recommends setting up Neverfail Heartbeat alerting to provide similar notifications. Please see Knowledgebase article #517 - 'How to configure and test alerting in Neverfail Heartbeat' and Knowledgebase article #517 - 'How to configure and test alerting in Neverfail Heartbeat' for further information.
Neverfail Heartbeat V5.0 and onwards