Hi,

I was trying to upgrade Exchange environment from Exchange 2010 to Exchange 2013. I installed Exchange 2013 in Windows 2012 R2 Server and migrated test mailbox, Later I updated Exchange CU7 but it left with OWA, ECP inaccessible. Later troubleshooting also made Powershell to inaccessible. So i decided to remove Exchange 2013 completely & I end up removing manually from ADSIEDIT since clean uninstall not allowing. I performed below steps while remove the exchange.

1. In AD i Removed this new Exchange 2013 server from Configuration partition using ADSIEDIT.

2. I removed the database associated to 2013 server through ADSIEDIT

3. Removed IIS and its directories from Exchange server

4. Removed the Exchange server directory

5. Removed Exchange server registry under hklm\Softwares\Exchange servers and all Exchange services from services registry as well.

6. I also removed migration mailbox user account from Active directory.

now when i tried re-installing, its failing with "Exception has been thrown by the target of an invocation" message and Event 4027 error (MSExchangeADAccess) in logs.

Any suggestion/help would be much apprec

Hi karthikeyan,

Thank you for your question.

We could refer to the following steps to check if the issue persist:

1.        Exit domain on this server
2.        Change server name to another one
3.        Join domain then install Exchange server

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim