A common issue being reported by Microsoft WebMatrix Beta users, is that they are unable to easily delete a SQL Server Compact Edition database from with WebMatrix itself. There is a way to delete the CE databases using the Files workspace of WebMatrix
Read More...
Read the complete post at http://blogs.iis.net/andrewpalmer/archive/2010/07/22/did-you-know-you-can-add-manage-and-delete-a-sql-server-compact-edition-database-from-webmatrix.aspx