How to enbale CLR integration mode in SQL Server

Common Language Runtime (CLR) integration is a powerful feature ofSQL Server. CLR integration was introduced in SQL Server 2005, and it has beenextended in SQL Server 2008. Prior to SQL Server 2005, it was necessary to create extended stored procedures (XP) using C++ to take advantage of functionality beyond that provided by SQL Server natively. Today, CLR integration provides you with the flexibility to define stored procedures, functions, triggers,
data types, and other database objects using either Transact-SQL or any .NET Framework language.The advantage of this approach is that you can choose the language more suited to the task at hand

sp_configure ‘show advanced options’, 1;

sp_configure ‘clr enabled’,1;


Ad hoc update to system catalogs is not supported.

Configuration option ‘show advanced options’ changed from 1 to 1. Run the RECONFIGURE statement to install.
Msg 5808, Level 16, State 1, Line 1
Ad hoc update to system catalogs is not supported.

to quick fix the above error use RECONFIGURE WITH OVERRIDE

Now, the reason why we are having that error is there is a setting called ‘allow updates’ which is a deprecated feature of SQL server 2000 , basically this allows the user to update the system tables directly in sql server although this feature is no longer available from SQL Server 2005 , but when this option is turned on or changed in SQL Sever 2005 or 2008 or R2, you will get an error message saying “Ad hoc update to system catalogs is not supported.” all though this feature is not supported then
why we are still receiving error ?, well when that option is changed, any “RECONFIGURE” is considered a side effect to the running server values but in this case if you use “WITH OVERRIDE” it worked as it overrides any warinings when we reconfigure

so do not use this feature