How to log into SQL Server Management Studio if there is no sysadmin account or you don’t know the password.
By default the Local System account on the SQL Server instance has sysadmin rights. In order to log into SQL Server Management Studio and assign another account sysadmin permissions, please follow the steps:
1. Download PSExec http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx
2. Run the following command in the command prompt, replace the wildcard with the number depending on deployed SQL Server version:
PsExec -s -i “C\:Program Files (x86)\Microsoft SQL Server\*\Tools\Binn\ManagementStudio\Ssms.exe”
3. The SQL Server Management Studio runs, after clicking Connect you will be connected with sysadmin permissions.
Note: SQL Server Management Studio might be installed at the different drive therefore you should change the path to “Ssms.exe” before running the command.