Error Description from SUMMARY.txt file of service pack upgrade : Machine : < ;server_name>; Product : Client Components Error : MSP Error: 29549 Failed to install and configure assemblies C:\Program Files\Microsoft SQL Server\90\NotificationServices\9.0.242\Bin\microsoft.sqlserver.notificationservices.dll in the COM+ catalog. Error: -2146233087 Error message: Unknown error 0x80131501 Error description: The Transaction Manager is not available. (Exception from HRESULT: 0x8004D01B) ————— Other errors logged in Windows Event logs:   System Log Error: 7024: The Distributed Transaction Coordinator (MS DTC) […]

While searching for questions, Why MSDTC is required, in which it needs to be configured, is it must for SQL Clustering, etc. Please find below the analysis done by going through several forums and msdn articles,