The ASP.NET SQL Server Registration tool is used to create a Microsoft SQL Server database for use by the SQL Server providers in ASP.NET, or to add or remove options from an existing database. The Aspnet_regsql.exe file is located in the [drive:]%windir%Microsoft.NETFrameworkversion folder on your Web server.
You can run Aspnet_regsql.exe without any command-line arguments to run a wizard that will walk you through specifying connection information for your SQL Server installation, and installing or removing the database elements for the membership, role management, profile, Web Parts personalization, and health monitoring features. (Setting session state and SQL cache dependency are not covered by the wizard.) You can also run Aspnet_regsql.exe as a command-line tool to specify database elements for individual features to add or remove, using the options listed in the table below. (from MSDN)
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