Failed to generate a user instance

Hi, 
On my windows Server 2012, I deployed my web application on iis but I get an error when previewing : 
Failed to generate a user instance of SQL Server due to a failure in starting the process for the user instance. The connection will be closed.
the solutions online like delete C:\Documents and Settings\USERNAME\Local Settings\Application Data\Microsoft\Microsoft SQL Server Data\SQLEXPRESS would not work because I don't have that folder under my username in the server.  (Local Settings folder doesn't exist)

Any hep please
Thanks