Failed to generate a user instance of SQL Server

I have just removed SQL Server Express 2012 and installed SQL Server Express 2014.  And now I keep getting the above message when I try to open a connection from Visual Basic using the same connection string I was using under 2012.  I am running Windows 8.1.
I have researched through this and other forums and the best advise seems to be to remove the files in c:\Users\user\appdata\local\microsoft\microsoft sql server unfortunately this folder does not exist in my microsoft folder.
What else can I look at.  I can open SSMS and attach the database in question, however when I try to attach from within the VB code I keep getting the above error.
BHend