SQL Server 2008 R2 services not coming online
Issue was resolved.. Actually improper build of sql server caused for issue. Check the registry key level for mssql server for what the default data, backup path existing in the host.. Go for same path in the explorer and check whether the database files existing in the same folder.. if not then msagent certificate will be not created in that path. 

Eg. Create a sample database in the server without mentioning a physical name then you will get a operating system error saying wrong path. 

So after applying the patch also one more msagent certificate will be created showing with version number..  this is the root cause of the issue