Unable to connect to database engine using built-in administrator account I am trying to connect to our SQL server 2012 database engine using SSMS but it fails with error 18456. I am logged in as the built-in administrator account on the windows server where the DB is installed and the database engine is configured to use Windows authentication. Details of the error in SQL server logs are as follows:

2016-08-30 11:04:01.290 Logon        Error: 18456, Severity: 14, State: 5.

 

2016-08-30 11:04:01.290 Logon        Login failed for user 'SERVERNAME\Administrator'. Reason: Could not find a login matching the name provided. [CLIENT: ]

 

I will appreciate any assistance resolving this problem.
Even though you are logged in as an administrator to the server were sql is running and installed, that login must still be a valid login in Sql Server with appropriate permission, is this the case?