In one case we noticed that SQL Server (SQL Server 2014) service was scheduled to start Automatically on system boot but still it was not starting up. It did not even start when we manually tried to start the service. We got following errors:
Error1: A timeout was reached (30000 milliseconds) while waiting for the SQL Server service to connect.
Error2: The SQL Server service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion.
On further investigation, we found that for starting the service automatically SQL Server needs an account with rights to start services at operating system startup.
To solve this issue you need to go:
1. Administrative Tools > Services or Type on Run Services.msc.
2. Then Choose SQL Server(MSSQLSERVER or the name of your instances) > Right Click > Properties > Move to Log On > Set the Log On option using a Local System Account.
3. If you have chosen this option, hit on Browse Button and find the Local Service Account or Network service Account there > Click on Apply.
4. Restart your computer and you will able to start your SQL Server.