Did you execute

Exec Sp_fulltext_service ‘load_os_resources’, 1

?
You'll have to restart the SQL Server service after that.

>I want to list all supported IFilter types by my database.
>
>I know "select document_type, path from sys.fulltext_document_types" but it doesn't list them all (doesn't list .xlsx, .zip, .rar, ... and they are working).
>
>I have also tried IFilter Explorer from http://www.citeknet.com/Products/IFilters/IFilterExplorer/tabid/62/Default.aspx and the SQL Server tab is returning me an error (and their support site doesn't return answers/comments).
>
>Are there any other way of listing available IFilters?