i've tried to connect my project to .mdf files and i used .\SQLEXPRESS but still i ended up the following errors,
The Data Source value in the connection sting specifies an instance of SQL Server that is not installed. To resolve this issue, you can either choose to install the matching instance of SQL Server or modify the Data Source value in the connection string.
here is connection string i used, but still i got the same error
Data Source=.\SQLEXPRESS;AttachDbFilename="C:\Users\Man-dela\Desktop\Visual Studio 2012\Projects\LibraryManagementSystem\LibraryManagementSystem\Database\LMS.mdf";Integrated Security=True;User Instance=True
can anyone help me