You will see see file types in the search window "type" column, You can order the files by clicking the "type" column title and files will appear in order of file type.
If you do not want particular types, you can enter, for instance .wma into the word filter in options > filters if you do not want wma files. This will not exclude all files of that type, but will help.
If you could search by file type that would have been well over a year ago ....
I hope this helps
