Err msg: filters required could not be installed

[Dorothy]

When I open a folder and want to search for a word(s) in
documents within that folder I get the following error
msg: "The filters required to perform this search could
not be installed. The search cannot be completed as
specified."

I have gone to File; Open; (I select the folder I want to
search within); Tools; @ Property, I select Contents; I
enter the text I want to search for and then click on
Find Now. Then I get the error message and it won't
complete the search.

Thanks for any help!