Install and Configure Full Text Search
You can install the Full Text Search from the feature selection wizard while installing the SQL server setup. You can get the step by step installation guide to check for the feature selection wizard from this article http://blogs.msdn.com/b/vincentbellet/archive/2009/11/10/sql-server-2008-r2-november-ctp-installation-step-by-step.aspx
How to know if Full Text Search feature is installed and enabled on SQL server
You can check whether Full Text Search (FTS) is installed on SQL Server by running following command. Below command will return value 1 if Full Text Search is installed on the current SQL server otherwise it will return value as 0.
You can check if Full Text Search is enabled on a particular Database by running below command. Below command will return value 1 if the Full Text Search is enabled on the database otherwise it will return value as 0.
For Example: select DATABASEPROPERTY('PaperSave','isfulltextenabled')
<databasename> mentioned in above command denotes the name of the database for which you want to check if Full Text Search is enabled or not. Moreover, please make sure to enter the Database Name in proper case.
For more information on how to configure Full text search manually on database, please go through the article from Microsoft: http://technet.microsoft.com/en-us/library/ms142497(v=sql.90).aspx