I’ve been chasing problems with MSDTC today. We were trying to get one machines on a different domain to use MSDTC through COM+ to talk to a remote SQL Server on a different domain.
Select / Read operations seemed to work fine but when it attempted to use an UPDATE method in a transaction, it failed with an exception saying
COM+ was unable to talk to the Microsoft Distributed Transaction Coordinator (Exception from HRESULT: 0x8004E00F)
The following information describes my eventual journey to success.