Q:

Change integrated security user of Content Manager

I installed Content Manager Server (SDL Web 8) with the Integrated Security database setting. I ran the installer under a user that had rights on the database. How can I change the user that was used when running the installer?

A:

If you configure CM to use Windows Integrated security to connect to MSSQL, it won't connect as the user who ran the installer, but with the identity of the CM Kernel host processes.
Typically, that means NETWORK SERVICE (TcmServiceHost.exe, TcmBatchProcessor.exe) and SYSTEM (TcmPublisher.exe)
Note that these identities are represented as the computer account (DOMAIN\COMPUTERNAME$) when accessing network resources.
So,indeed, you should configure MSSQL to allow logins from computer accounts from all CM servers.

