Remove a query in Query Manager

I am trying to remove a query that was generated by me under "Formatted Searches" in Query Manager. When I select the query and click on Remove button then it gives me the message "would you like to remove this query?" then I select "yes" but I get this message:

The query is used with user-defined values [message 952-23]

Please let me know the steps how I can delete this query.

Thanks in advance.

-Bill