One series of events that might occur, requiring the removal and reinstallation of the Event Service is:
Event ID : 0 Source : MSExchangeES Type : Informational Category : General Description: The Microsoft Exchange Event Service (5.5.1960.3) Started successfully. Event ID : 5 Source : MSExchangeES Type : Error Category : General Description: An unexpected MAPI error occurred. Error returned was [0x80004005]. Event ID : 1 Source : MSExchangeES Type : Informational Category : General Description: The Microsoft Exchange Event Service stopped successfully.
Before removing the Event Service as a solution, verify that this server is a public folder server. If the server is not a public folder server, the Events Service will not start. For additional information, please refer to the following article in the Microsoft Knowledge Base, which explains this requirement in more detail:
182082
: XADM: Event Service Won't Start If Alternate PF Server Selected