hie

Below I am mentioning the steps you need to perform that may help you with this situations.

1 - SQL Server and SQL Serve Agent services in SSMS are needed to be stopped first .

2 - Go on Start then on Run and click on cmd and press 'OK' button and navigate to SQL Server's Binn directory.

3 - Run 'sqlservr -m' command , this will start your SQL server in single user mode after entering into SQL server Binn directory.

Note:- This process may need time, as soon the SQL server is in single user mode " Recovery is completed.This is a international message only. No user action required.

4 - Now open a new command prompt window, use sqlcmd utility to connect to your SQL server instance:-

Use -S parameter along with full name (if you have named your instance). Also can you use E switch for trusted connections. And fortunately if you are a Windows local administrator you will get access to the server.

5 - Now you can add BUILTIN\Administrators group to the instance and can create a login as you are connected to the server as SYSADMIN rights. You can also add DBA Windows domain group in your admin login.

6 - Assign roles to your created login.

7 - Now you can access to SSMS and connect the instance using newly created login.

I hope that these steps will help you. Feel free to ask.

Thanks & Regards