I want to keep this post short so I'll dive right into the issue.
When you first configure a server with HFM components on it the first time you configure DCOM it will run a "pre-configuration" task. This involves registering some DLL files and using DISM to reconfigure the server.
Any subsequent runs of the "Configure DCOM" task in HFM will miss out this pre-configuration step. So if you find yourself needing to re-configure DCOM (perhaps due to Windows patching) it is possible that not everything required will re-register.
The way to fix this is simple, we just run the commands below (fit for your environment, obviously):
cd /d E:\Oracle\Middleware\user_projects\epmsystem1\bin
resetConfigTask.bat -product HFM -task preConfiguration
Then when you go to run the "Configure DCOM" task in the configtool it will also include this "pre-configuration" step as well.
You may have read about this resetConfigTask.bat script elsewhere online, I actually found about the command here: http://epm-errors.blogspot.co.uk/2013/01/resetconfigtaskbat.html