by default sql server 2005 does not have Intellisense installed in it,
While writing SQL statements, we need to recall the database table structure (including columns, their data types, size) and other database objects structure like stored procedure, view and functions again and again. Sometimes it becomes tedious task.,
so intellisense makes your work easy, download its free version from here http://www.devart.com/dbforge/sql/sqlcomplete/
and run the setup it is the small file, and after installing open the sqlserver and at the top you will find Sql Complete menu option
it indicates that Intellisense installed successfully..it is very usefull tool
Now, whenever you will write your SQL query, it will provides the intellisense help like Visual Studio.