Adding an Extended Stored Procedure to SQL Server
A DLL that contains extended stored procedure functions acts as an extension to Microsoft® SQL Server™. To install the DLL, copy the file to the directory containing the standard SQL Server DLL files (C:\Program Files\Microsoft SQL Server\Mssql\Binn by default).
To add each extended stored procedure function in an extended stored procedure DLL, a SQL Server system administrator must run the sp_addextendedproc system stored procedure, specifying the name of the function and the name of the DLL in which that function resides. For example, this command registers the function xp_hello, located in xp_hello.dll, as a SQL Server extended stored procedure:
sp_addextendedproc 'xp_hello', 'xp_hello.dll'
It is not necessary to stop and restart SQL Server. This is in a sample only available if you select Dev Tools during setup.