I'm seeing some odd behaviour with SQL Server 2012 Express Edition, where a sysadmin user does not have permission to create databases.
The evolution of this installation has been somewhat trying:
- Host machine initialised
- SQL Server 2012 Express Edition installed on Virtual Machine
- Host machine renamed and joined to the domain
- Domain rebuilt and machine re-joined to the domain
The sysadmin user that is suffering the problems is a domain user. The user appears in the Security -> Logins node in SSMS, and the sysadmin box is checked on the user's "Server Roles" properties. However, the sysadmin properties don't appear to have "taken": when I log into SSMS as this user, I don't see ~80% of the users configured on this server, and the CREATE DATABASE permissions are denied. There are probably other symptoms hiding as well.
I have read this related question, and I do not believe I am suffering the same problem: the solution proposed in that question is to make the problematic user a sysadmin, which I have already done.
If you're relying on the builtin "Administrators" group membership to grant "sa" rights to a use be sure you're running SQL Management Studio elevated, otherwise your user isn't an "Administrator" and, ergo, won't have "sa" rights either.