SQL Error 1069: The service did not start due to a logon Failure.

As the error message says it is a log on failure, maybe the password data in registry is damage or the credentials for that services is change.

Check first the network if it is connected or getting the right IP address.

Go to Control Panel/Administrative Tools>Services locate for MSSQLSERVER service right click then properties. Click log on tab then change the Username and Password, or just check the local system click Apply. 

Then on the General tab click start.

Hope it solves your problem.