Attach database failed for Server. (Microsoft.SqlServer.Smo) An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo) Unable to open the physical file . Operating system error 5: "5(Access is denied.)". (Microsoft SQL Server, Error: 5120)

Connect to the server using an administrator account with access to the file system for the database files and through Windows Authentication rather than using sa through SQL Server Authentication.