Windows 7 Home Premium (64-bit), VS2010 Pro, SQL Server Express 2008 R2 (tried both x86 and x64)
Error showing in visual studio
The database 'C:\USERS\SWATI\DOCUMENTS\VISUAL STUDIO 2010\PROJECTS\ONLINE SHOPPING CART ASP.NET WEBFORM\C#\MYPROJECT\APP_DATA\SHOPING.MDF' cannot be opened because it is version 661. This server supports version 655 and earlier. A downgrade path is not supported.
Could not open new database 'C:\USERS\SWATI\DOCUMENTS\VISUAL STUDIO 2010\PROJECTS\ONLINE SHOPPING CART ASP.NET WEBFORM\C#\MYPROJECT\APP_DATA\SHOPING.MDF'. CREATE DATABASE is aborted.
An attempt to attach an auto-named database for file C:\Users\SWATI\Documents\Visual Studio 2010\Projects\Online Shopping Cart Asp.Net WebForm\C#\MyProject\App_Data\shoping.mdf failed. A database with the same name exists, or specified file cannot be opened,
or it is located on UNC share.