We needed to change the SQL Service Account for the SQL Server Database Engine & Agent Services from Local System as it has extensive predigests.
What are the things that we should do to test within the SQL Server database itself to ensure that there are no issues / permission problems with this change?
Note the service has been changed, and seems to be running fine Both Agent Services / SQL Server Engine.
The two versions we are implementing this in are SQL Server 2008 R2 and SQL Server 2012.
Best Answer
In Short: Everything and Anything. And Nothing.
But seriously: A few thoughts about changing the SQL Server service account:
In your particular case though - you are moving from one special privileged account to another. As you have seen - you were safe and things worked. I would also take this time to question the choice of the service account.
Are you on a domain? Why not use a domain user account per the best practices? The local accounts with special privileges are not the most secure or reliable service account choices. This article from Microsoft explains more there.