When there is a need to change settings of an existing Ms SQL database you will need to add ASP.NET SQL Server Registration into windows registry.
It can be done using the following method.
Navigate to [drive:]\%windir%\Microsoft.NET\Framework\version folder on your Web server, and type aspnet_regsql on the command prompt.
E.g.:
C:\>cd
Windows
C:\Windows>cd
Microsoft.NET
C:\Windows\Microsoft.NET>cd
Framework
C:\Windows\Microsoft.NET\Framework>cd
v2.0.50727
C:\Windows\Microsoft.NET\Framework\v2.0.50727>aspnet_regsql
After registering this functionality existing settings of existing databases can be altered after creation.
More information on the tool can be found on the following reference link.
Reference: http://msdn.microsoft.com/en-us/library/ms229862%28v=vs.80%29.aspx