Hi Ambuj
You can use the below 2 scripts to check wether ur SQL server is running or not
-- This Gives u the state of SQL server, Running or Stopped
master.dbo.xp_servicecontrol 'QueryState', 'MSSQLServer'
-- You can start or stop SQL server with the line below from DOS Prompt
Net Start MSSQLServer
Remember to Start SQL Server Agent once you have started
Hope this helps