Setting the MS-SQL compatibility levels

sp_dbcmptlevel : This command is using to set certain database behaviors to be compatible with the specified version of SQL Servers.

Example:

   —-SQL Server 2005 database compatible level to SQL Server 2000
EXEC sp_dbcmptlevel <DBNAME>, 80;
GO

Version of SQL Server database can be one of the following:

• 60 = SQL Server 6.0
• 65 = SQL Server 6.5
• 70 = SQL Server 7.0
• 80 = SQL Server 2000
• 90 = SQL Server 2005

Please find the full post in Pinal Dave’s Blog

Reference : http://blog.sqlauthority.com/2007/05/29/sql-server-2005-change-database-compatible-level-backward-compatibility/