DbNetTime will run against SQL Server Compact which is included in the download and can be selected as part of the install process. Alternatively Microsoft provide an free version of SQL Server called SQL Server 2008 Express which can be downloaded via the link below: http://www.microsoft.com/express/database/ You should install this before installing DbNetTime

If you are using Windows authentication to access the SQL Server database you will need to ensure that all the windows accounts that are accessing the DbNetTime database have been granted permission to do so. You can do this in Enterprise Manager or Management Studio