If you’re running Visual Studio 2008 sp1 and Sql Server 2008 in Vista x64, then you’ve probably come across the error when creating a database:
“Connections to SQL Server files (*.mdf) require SQL Server Express 2005 to function properly. Please verify the installation of the component of download from the URL:
It took me several days with no real solution until I found a reference to http://support.microsoft.com/kb/957944
Apparently there is a bug with VS2008 and Sql Server Express 2008 in that some of the files aren’t properly registered, so it doesn’t realize that you have a valid sql server install. And to make matters worse for finding the solution, it only happens if you are using x64 everything.
You’ll have to email Microsoft to get the Hotfix, or install 32bit sql server express.
For me, the Hotfix did work.